diff --git a/app/call_centers/call_center_agent_edit.php b/app/call_centers/call_center_agent_edit.php
index 967685eba9..9c057d4c8e 100644
--- a/app/call_centers/call_center_agent_edit.php
+++ b/app/call_centers/call_center_agent_edit.php
@@ -47,14 +47,14 @@
 	$text = $language->get();
 
 //check for duplicates
-	if ($_GET["check"] == 'duplicate') {
+	if (!empty($_GET["check"]) == 'duplicate') {
 		//agent id
-			if ($_GET["agent_id"] != '') {
+			if (!empty($_GET["agent_id"])) {
 				$sql = "select agent_name ";
 				$sql .= "from v_call_center_agents ";
 				$sql .= "where agent_id = :agent_id ";
 				$sql .= "and domain_uuid = :domain_uuid ";
-				if (is_uuid($_GET["agent_uuid"])) {
+				if (!empty($_GET["agent_uuid"]) && is_uuid($_GET["agent_uuid"])) {
 					$sql .= " and call_center_agent_uuid <> :call_center_agent_uuid ";
 					$parameters['call_center_agent_uuid'] = $_GET["agent_uuid"];
 				}
@@ -62,7 +62,7 @@
 				$parameters['domain_uuid'] = $_SESSION['domain_uuid'];
 				$database = new database;
 				$row = $database->select($sql, $parameters, 'row');
-				if (is_array($row) && sizeof($row) != 0 && $row['agent_name'] != '') {
+				if (!empty($row) && !empty($row['agent_name'])) {
 					echo $text['message-duplicate_agent_id'].(if_group("superadmin") ? ": ".$row["agent_name"] : null);
 				}
 				unset($sql, $parameters);
@@ -72,7 +72,7 @@
 	}
 
 //action add or update
-	if (is_uuid($_REQUEST["id"])) {
+	if (!empty($_REQUEST["id"]) && is_uuid($_REQUEST["id"])) {
 		$action = "update";
 		$call_center_agent_uuid = $_REQUEST["id"];
 	}
@@ -81,7 +81,7 @@
 	}
 
 //get http post variables and set them to php variables
-	if (is_array($_POST)) {
+	if (!empty($_POST)) {
 		$call_center_agent_uuid = $_POST["call_center_agent_uuid"];
 		$user_uuid = $_POST["user_uuid"];
 		$agent_name = $_POST["agent_name"];
@@ -101,7 +101,7 @@
 	}
 
 //process the user data and save it to the database
-	if (count($_POST) > 0 && empty($_POST["persistformvar"])) {
+	if (!empty($_POST) && empty($_POST["persistformvar"])) {
 
 		//validate the token
 			$token = new token;
@@ -287,7 +287,7 @@
 	$destination = new destinations;
 
 //pre-populate the form
-	if (is_uuid($_GET["id"]) && $_POST["persistformvar"] != "true") {
+	if (!empty($_GET["id"]) && is_uuid($_GET["id"]) && empty($_POST["persistformvar"])) {
 		$call_center_agent_uuid = $_GET["id"];
 		$sql = "select * from v_call_center_agents ";
 		$sql .= "where domain_uuid = :domain_uuid ";
@@ -296,7 +296,7 @@
 		$parameters['call_center_agent_uuid'] = $call_center_agent_uuid;
 		$database = new database;
 		$row = $database->select($sql, $parameters, 'row');
-		if (is_array($row) && @sizeof($row) != 0) {
+		if (!empty($row)) {
 			$call_center_agent_uuid = $row["call_center_agent_uuid"];
 			$user_uuid = $row["user_uuid"];
 			$agent_name = $row["agent_name"];
@@ -401,7 +401,7 @@
 	echo "	".$text['label-agent_name']."\n";
 	echo "</td>\n";
 	echo "<td width='70%' class='vtable' align='left'>\n";
-	echo "	<input class='formfld' type='text' name='agent_name' maxlength='255' value=\"".escape($agent_name)."\" />\n";
+	echo "	<input class='formfld' type='text' name='agent_name' maxlength='255' value=\"".escape($agent_name ?? '')."\" />\n";
 	/*
 	echo "<select id=\"agent_name\" name=\"agent_name\" class='formfld'>\n";
 	echo "<option value=\"\"></option>\n";
@@ -460,7 +460,7 @@
 	echo "			</select>";
 	unset($users);
 	echo "			<br>\n";
-	echo "			".$text['description-users']."\n";
+	echo "			".!empty($text['description-users'])."\n";
 	echo "		</td>";
 	echo "	</tr>";
 
@@ -469,7 +469,7 @@
 	echo "	".$text['label-agent_id']."\n";
 	echo "</td>\n";
 	echo "<td class='vtable' align='left'>\n";
-	echo "  <input class='formfld' type='number' name='agent_id' id='agent_id' maxlength='255' min='1' step='1' value='".escape($agent_id)."'>\n";
+	echo "  <input class='formfld' type='number' name='agent_id' id='agent_id' maxlength='255' min='1' step='1' value='".escape($agent_id ?? '')."'>\n";
 	echo "	<div style='display: none;' id='duplicate_agent_id_response'></div>\n";
 	echo "<br />\n";
 	echo $text['description-agent_id']."\n";
@@ -481,7 +481,7 @@
 	echo "	".$text['label-agent_password']."\n";
 	echo "</td>\n";
 	echo "<td class='vtable' align='left'>\n";
-	echo "  <input class='formfld' type='password' name='agent_password' autocomplete='off' onmouseover=\"this.type='text';\" onfocus=\"this.type='text';\" onmouseout=\"if (!\$(this).is(':focus')) { this.type='password'; }\" onblur=\"this.type='password';\" maxlength='255' min='1' step='1' value='".escape($agent_password)."'>\n";
+	echo "  <input class='formfld' type='password' name='agent_password' autocomplete='off' onmouseover=\"this.type='text';\" onfocus=\"this.type='text';\" onmouseout=\"if (!\$(this).is(':focus')) { this.type='password'; }\" onblur=\"this.type='password';\" maxlength='255' min='1' step='1' value='".escape($agent_password ?? '')."'>\n";
 	echo "<br />\n";
 	echo $text['description-agent_password']."\n";
 	echo "</td>\n";
@@ -492,7 +492,7 @@
 	echo "	".$text['label-contact']."\n";
 	echo "</td>\n";
 	echo "<td class='vtable' align='left'>\n";
-	echo $destination->select('user_contact', 'agent_contact', $agent_contact);
+	echo $destination->select('user_contact', 'agent_contact', !empty($agent_contact));
 	echo "<br />\n";
 	echo $text['description-contact']."\n";
 	echo "</td>\n";
diff --git a/app/call_centers/call_center_agents.php b/app/call_centers/call_center_agents.php
index 26e19865ca..eec639110c 100644
--- a/app/call_centers/call_center_agents.php
+++ b/app/call_centers/call_center_agents.php
@@ -46,15 +46,18 @@
 	$language = new text;
 	$text = $language->get();
 
+//set from session variables
+	$list_row_edit_button = !empty($_SESSION['theme']['list_row_edit_button']['boolean']) ? $_SESSION['theme']['list_row_edit_button']['boolean'] : 'false';
+
 //get posted data
-	if (is_array($_POST['call_center_agents'])) {
+	if (!empty($_POST['call_center_agents'])) {
 		$action = $_POST['action'];
 		$search = $_POST['search'];
 		$call_center_agents = $_POST['call_center_agents'];
 	}
 
 //process the http post data by action
-	if ($action != '' && is_array($call_center_agents) && @sizeof($call_center_agents) != 0) {
+	if (!empty($action) && !empty($call_center_agents)) {
 		switch ($action) {
 			case 'delete':
 				if (permission_exists('call_center_agent_delete')) {
@@ -69,11 +72,11 @@
 	}
 
 //get http variables and set them to php variables
-	$order_by = $_GET["order_by"];
-	$order = $_GET["order"];
+	$order_by = $_GET["order_by"] ?? '';
+	$order = $_GET["order"] ?? '';
 
 //add the search term
-	$search = strtolower($_GET["search"]);
+	$search = strtolower($_GET["search"] ?? '');
 	if (!empty($search)) {
 		$sql_search = " (";
 		$sql_search .= "lower(agent_name) like :search ";
@@ -85,23 +88,23 @@
 //get total call center agent count from the database
 	$sql = "select count(*) from v_call_center_agents ";
 	$sql .= "where true ";
-	if ($_GET['show'] != "all" || !permission_exists('call_center_all')) {
+	if (!empty($_GET['show']) != "all" || !permission_exists('call_center_all')) {
 		$sql .= "and (domain_uuid = :domain_uuid or domain_uuid is null) ";
 		$parameters['domain_uuid'] = $_SESSION['domain_uuid'];
 	}
-	if (isset($sql_search)) {
+	if (!empty($sql_search)) {
 		$sql .= "and ".$sql_search;
 	}
 	$database = new database;
-	$num_rows = $database->select($sql, $parameters, 'column');
+	$num_rows = $database->select($sql, $parameters ?? null, 'column');
 
 //prepare to page the results
-	$rows_per_page = ($_SESSION['domain']['paging']['numeric'] != '') ? $_SESSION['domain']['paging']['numeric'] : 50;
+	$rows_per_page = (!empty($_SESSION['domain']['paging']['numeric'])) ? $_SESSION['domain']['paging']['numeric'] : 50;
 	$param = "&search=".urlencode($search);
-	if ($_GET['show'] == "all" && permission_exists('call_center_all')) {
+	if (!empty($_GET['show']) == "all" && permission_exists('call_center_all')) {
 		$param .= "&show=all";
 	}
-	$page = $_GET['page'];
+	$page = $_GET['page'] ?? '';
 	if (empty($page)) { $page = 0; $_GET['page'] = 0; }
 	list($paging_controls, $rows_per_page) = paging($num_rows, $param, $rows_per_page);
 	list($paging_controls_mini, $rows_per_page) = paging($num_rows, $param, $rows_per_page, true);
@@ -112,7 +115,7 @@
 	$sql .= order_by($order_by, $order, 'agent_name', 'asc');
 	$sql .= limit_offset($rows_per_page, $offset);
 	$database = new database;
-	$result = $database->select($sql, $parameters, 'all');
+	$result = $database->select($sql, $parameters ?? null, 'all');
 	unset($sql, $parameters);
 
 //create token
@@ -142,7 +145,7 @@
 	}
 	echo 		"<form id='form_search' class='inline' method='get'>";
 	if (permission_exists('call_center_all')) {
-		if ($_GET['show'] == 'all') {
+		if (!empty($_GET['show']) == 'all') {
 			echo "		<input type='hidden' name='show' value='all'>";
 		}
 		else {
@@ -175,10 +178,10 @@
 	echo "<tr class='list-header'>\n";
 	if (permission_exists('call_center_agent_delete')) {
 		echo "	<th class='checkbox'>\n";
-		echo "		<input type='checkbox' id='checkbox_all' name='checkbox_all' onclick='list_all_toggle(); checkbox_on_change(this);' ".($result ?: "style='visibility: hidden;'").">\n";
+		echo "		<input type='checkbox' id='checkbox_all' name='checkbox_all' onclick='list_all_toggle(); checkbox_on_change(this);' ".(!empty($result) ?: "style='visibility: hidden;'").">\n";
 		echo "	</th>\n";
 	}
-	if ($_GET['show'] == "all" && permission_exists('call_center_all')) {
+	if (!empty($_GET['show']) == "all" && permission_exists('call_center_all')) {
 		echo th_order_by('domain_name', $text['label-domain'], $order_by, $order, $param, "class='shrink'");
 	}
 	//echo th_order_by('domain_uuid', 'domain_uuid', $order_by, $order);
@@ -192,12 +195,12 @@
 	//echo th_order_by('agent_wrap_up_time', $text['label-wrap_up_time'], $order_by, $order);
 	//echo th_order_by('agent_reject_delay_time', $text['label-reject_delay_time'], $order_by, $order);
 	//echo th_order_by('agent_busy_delay_time', $text['label-busy_delay_time'], $order_by, $order);
-	if (permission_exists('call_center_agent_edit') && $_SESSION['theme']['list_row_edit_button']['boolean'] == 'true') {
+	if (permission_exists('call_center_agent_edit') && $list_row_edit_button == 'true') {
 		echo "	<td class='action-button'>&nbsp;</td>\n";
 	}
 	echo "</tr>\n";
 
-	if (is_array($result)) {
+	if (!empty($result)) {
 		$x = 0;
 		foreach($result as $row) {
 			if (permission_exists('call_center_agent_edit')) {
@@ -210,7 +213,7 @@
 				echo "		<input type='hidden' name='call_center_agents[$x][uuid]' value='".escape($row['call_center_agent_uuid'])."' />\n";
 				echo "	</td>\n";
 			}
-			if ($_GET['show'] == "all" && permission_exists('call_center_all')) {
+			if (!empty($_GET['show']) == "all" && permission_exists('call_center_all')) {
 				if (!empty($_SESSION['domains'][$row['domain_uuid']]['domain_name'])) {
 					$domain = $_SESSION['domains'][$row['domain_uuid']]['domain_name'];
 				}
@@ -239,7 +242,7 @@
 				$sql .= "where gateway_uuid = :gateway_uuid ";
 				$parameters['gateway_uuid'] = $bridge_statement[2];
 				$database = new database;
-				$result = $database->select($sql, $parameters, 'all');
+				$result = $database->select($sql, $parameters ?? null, 'all');
 				if (count($result) > 0) {
 					$gateway_name = $result[0]['gateway'];
 					$agent_contact = str_replace($bridge_statement[2], $gateway_name, $agent_contact);
@@ -252,7 +255,7 @@
 			//echo "	<td>".$row[agent_wrap_up_time]."</td>\n";
 			//echo "	<td>".$row[agent_reject_delay_time]."</td>\n";
 			//echo "	<td>".$row[agent_busy_delay_time]."</td>\n";
-			if (permission_exists('call_center_agent_edit') && $_SESSION['theme']['list_row_edit_button']['boolean'] == 'true') {
+			if (permission_exists('call_center_agent_edit') && $list_row_edit_button == 'true') {
 				echo "	<td class='action-button'>";
 				echo button::create(['type'=>'button','title'=>$text['button-edit'],'icon'=>$_SESSION['theme']['button_icon_edit'],'link'=>$list_row_url]);
 				echo "	</td>\n";
diff --git a/app/call_centers/call_center_queue_edit.php b/app/call_centers/call_center_queue_edit.php
index 2cee4c4e8b..c69bf5f588 100644
--- a/app/call_centers/call_center_queue_edit.php
+++ b/app/call_centers/call_center_queue_edit.php
@@ -47,7 +47,7 @@
 	$text = $language->get();
 
 //action add or update
-	if (is_uuid($_REQUEST["id"])) {
+	if (!empty($_REQUEST["id"]) && is_uuid($_REQUEST["id"])) {
 		$action = "update";
 		$call_center_queue_uuid = $_REQUEST["id"];
 	}
@@ -60,12 +60,12 @@
 
 //get total call center queues count from the database, check limit, if defined
 	if ($action == 'add') {
-		if ($_SESSION['limit']['call_center_queues']['numeric'] != '') {
+		if (!empty($_SESSION['limit']['call_center_queues']['numeric'])) {
 			$sql = "select count(*) from v_call_center_queues ";
 			$sql .= "where domain_uuid = :domain_uuid ";
 			$parameters['domain_uuid'] = $_SESSION['domain_uuid'];
 			$database = new database;
-			$total_call_center_queues = $database->select($sql, $parameters, 'column');
+			$total_call_center_queues = $database->select($sql, $parameters ?? null, 'column');
 			unset($sql, $parameters);
 
 			if ($total_call_center_queues >= $_SESSION['limit']['call_center_queues']['numeric']) {
@@ -77,7 +77,7 @@
 	}
 
 //get http post variables and set them to php variables
-	if (is_array($_POST)) {
+	if (!empty($_POST)) {
 		//get the post variables a run a security chack on them
 			//$domain_uuid = $_POST["domain_uuid"];
 			$dialplan_uuid = $_POST["dialplan_uuid"];
@@ -119,7 +119,7 @@
 	}
 
 //delete the tier (agent from the queue)
-	if ($_REQUEST["a"] == "delete" && is_uuid($_REQUEST["id"]) && permission_exists("call_center_tier_delete")) {
+	if (!empty($_REQUEST["a"]) && $_REQUEST["a"] == "delete" && is_uuid($_REQUEST["id"]) && permission_exists("call_center_tier_delete")) {
 		//set the variables
 			$call_center_queue_uuid = $_REQUEST["id"];
 			$call_center_tier_uuid = $_REQUEST["call_center_tier_uuid"];
@@ -133,10 +133,10 @@
 			$parameters['domain_uuid'] = $_SESSION['domain_uuid'];
 			$parameters['call_center_tier_uuid'] = $call_center_tier_uuid;
 			$database = new database;
-			$tiers = $database->select($sql, $parameters, 'all');
+			$tiers = $database->select($sql, $parameters ?? null, 'all');
 			unset($sql, $parameters);
 
-			if (is_array($tiers) && sizeof($tiers) != 0) {
+			if (!empty($tiers)) {
 				foreach ($tiers as &$row) {
 					$call_center_agent_uuid = $row["call_center_agent_uuid"];
 					$call_center_queue_uuid = $row["call_center_queue_uuid"];
@@ -175,7 +175,7 @@
 	}
 
 //process the user data and save it to the database
-	if (count($_POST) > 0 && empty($_POST["persistformvar"])) {
+	if (!empty($_POST) && empty($_POST["persistformvar"])) {
 
 		//get the uuid from the POST
 			if ($action == "update") {
@@ -242,7 +242,7 @@
 
 		//update the call centier tiers array
 			$x = 0;
-			if (is_array($_POST["call_center_tiers"]) && @sizeof($_POST["call_center_tiers"]) != 0) {
+			if (!empty($_POST["call_center_tiers"])) {
 				foreach ($_POST["call_center_tiers"] as $row) {
 					//add the domain_uuid
 						if (empty($row["domain_uuid"])) {
@@ -264,7 +264,7 @@
 			$queue_timeout_data = implode($action_array);
 
 		//add the recording path if needed
-			if ($queue_greeting != '') {
+			if (!empty($queue_greeting)) {
 				if (file_exists($_SESSION['switch']['recordings']['dir'].'/'.$_SESSION['domain_name'].'/'.$queue_greeting)) {
 					$queue_greeting_path = $_SESSION['switch']['recordings']['dir'].'/'.$_SESSION['domain_name'].'/'.$queue_greeting;
 				}
@@ -316,7 +316,7 @@
 			$array['call_center_queues'][0]['domain_uuid'] = $domain_uuid;
 			
 			$y = 0;
-			if (is_array($_POST["call_center_tiers"]) && @sizeof($_POST["call_center_tiers"]) != 0) {
+			if (!empty($_POST["call_center_tiers"])) {
 				foreach ($_POST["call_center_tiers"] as $row) {
 					if (is_uuid($row['call_center_tier_uuid'])) {
 						$call_center_tier_uuid = $row['call_center_tier_uuid'];
@@ -418,12 +418,12 @@
 			$cache->delete("dialplan:".$_SESSION["domain_name"]);
 
 		//clear the destinations session array
-			if (isset($_SESSION['destinations']['array'])) {
+			if (!empty($_SESSION['destinations']['array'])) {
 				unset($_SESSION['destinations']['array']);
 			}
 
 		//redirect the user
-			if (isset($action)) {
+			if (!empty($action)) {
 				if ($action == "add") {
 					message::add($text['message-add']);
 				}
@@ -441,7 +441,7 @@
 			$tier_level = $_POST["tier_level"];
 			$tier_position = $_POST["tier_position"];
 
-			if ($agent_name != '') {
+			if (!empty($agent_name)) {
 				//setup the event socket connection
 					$fp = event_socket_create($_SESSION['event_socket_ip_address'], $_SESSION['event_socket_port'], $_SESSION['event_socket_password']);
 				//add the agent using event socket
@@ -489,7 +489,7 @@
 	} //(count($_POST)>0 && empty($_POST["persistformvar"]))
 
 //pre-populate the form
-	if (is_array($_GET) && is_uuid($_GET["id"]) && $_POST["persistformvar"] != "true") {
+	if (!empty($_GET) && is_uuid($_GET["id"]) && empty($_POST["persistformvar"])) {
 		$call_center_queue_uuid = $_GET["id"];
 		$sql = "select * from v_call_center_queues ";
 		$sql .= "where domain_uuid = :domain_uuid ";
@@ -497,10 +497,10 @@
 		$parameters['domain_uuid'] = $_SESSION['domain_uuid'];
 		$parameters['call_center_queue_uuid'] = $call_center_queue_uuid;
 		$database = new database;
-		$call_center_queues = $database->select($sql, $parameters, 'all');
+		$call_center_queues = $database->select($sql, $parameters ?? null, 'all');
 		unset($sql, $parameters);
 
-		if (is_array($call_center_queues)) {
+		if (!empty($call_center_queues)) {
 			foreach ($call_center_queues as &$row) {
 				$queue_name = $row["queue_name"];
 				$dialplan_uuid = $row["dialplan_uuid"];
@@ -543,9 +543,9 @@
 	$sql .= "and t.domain_uuid = :domain_uuid ";
 	$sql .= "order by tier_level asc, tier_position asc, a.agent_name asc";
 	$parameters['domain_uuid'] = $_SESSION['domain_uuid'];
-	$parameters['call_center_queue_uuid'] = $call_center_queue_uuid;
+	$parameters['call_center_queue_uuid'] = $call_center_queue_uuid ?? null;
 	$database = new database;
-	$tiers = $database->select($sql, $parameters, 'all');
+	$tiers = $database->select($sql, $parameters ?? null, 'all');
 	unset($sql, $parameters);
 
 //add an empty row to the tiers array
@@ -560,7 +560,7 @@
 	for ($x = 0; $x < $rows; $x++) {
 		$tiers[$id]['call_center_tier_uuid'] = uuid();
 		$tiers[$id]['call_center_agent_uuid'] = '';
-		$tiers[$id]['call_center_queue_uuid'] = $call_center_queue_uuid;
+		$tiers[$id]['call_center_queue_uuid'] = $call_center_queue_uuid ?? null;
 		$tiers[$id]['tier_level'] = '';
 		$tiers[$id]['tier_position'] = '';
 		$tiers[$id]['agent_name'] = '';
@@ -573,7 +573,7 @@
 	$sql .= "order by agent_name asc";
 	$parameters['domain_uuid'] = $_SESSION['domain_uuid'];
 	$database = new database;
-	$agents = $database->select($sql, $parameters, 'all');
+	$agents = $database->select($sql, $parameters ?? null, 'all');
 	unset($sql, $parameters);
 
 //get the sounds
@@ -605,7 +605,7 @@
 	$sql .= "order by recording_name asc ";
 	$parameters['domain_uuid'] = $_SESSION['domain_uuid'];
 	$database = new database;
-	$recordings = $database->select($sql, $parameters, 'all');
+	$recordings = $database->select($sql, $parameters ?? null, 'all');
 	unset($sql, $parameters);
 
 //get the phrases
@@ -613,7 +613,7 @@
 	$sql .= "where (domain_uuid = :domain_uuid or domain_uuid is null) ";
 	$parameters['domain_uuid'] = $domain_uuid;
 	$database = new database;
-	$phrases = $database->select($sql, $parameters, 'all');
+	$phrases = $database->select($sql, $parameters ?? null, 'all');
 	unset($sql, $parameters);
 
 //show the header
@@ -626,7 +626,7 @@
 	require_once "resources/header.php";
 
 //only allow a uuid
-	if (!is_uuid($call_center_queue_uuid)) {
+	if (!empty($call_center_queue_uuid) && !is_uuid($call_center_queue_uuid)) {
 		$call_center_queue_uuid = null;
 	}
 
@@ -698,7 +698,7 @@
 	echo "	".$text['label-queue_name']."\n";
 	echo "</td>\n";
 	echo "<td width='70%' class='vtable' align='left'>\n";
-	echo "	<input class='formfld' type='text' name='queue_name' maxlength='255' value=\"".escape($queue_name)."\" required='required'>\n";
+	echo "	<input class='formfld' type='text' name='queue_name' maxlength='255' value=\"".escape($queue_name ?? '')."\" required='required'>\n";
 	echo "<br />\n";
 	echo $text['description-queue_name']."\n";
 	echo "</td>\n";
@@ -709,7 +709,7 @@
 	echo "	".$text['label-extension']."\n";
 	echo "</td>\n";
 	echo "<td class='vtable' align='left'>\n";
-	echo "	<input class='formfld' type='number' name='queue_extension' maxlength='255' min='0' step='1' value=\"".escape($queue_extension)."\" required='required'>\n";
+	echo "	<input class='formfld' type='number' name='queue_extension' maxlength='255' min='0' step='1' value=\"".escape($queue_extension ?? '')."\" required='required'>\n";
 	echo "<br />\n";
 	echo $text['description-extension']."\n";
 	echo "</td>\n";
@@ -809,7 +809,7 @@
 	echo "</td>\n";
 	echo "</tr>\n";
 
-	if (permission_exists('call_center_tier_view') && is_array($agents) && count($agents) > 0) {
+	if (permission_exists('call_center_tier_view') && !empty($agents)) {
 		echo "<tr>";
 		echo "	<td class='vncell' valign='top'>".$text['label-agents']."</td>";
 		echo "	<td class='vtable' align='left'>";
@@ -821,7 +821,7 @@
 		echo "				<td></td>\n";
 		echo "			</tr>\n";
 		$x = 0;
-		if (is_array($tiers)) {
+		if (!empty($tiers)) {
 			foreach($tiers as $field) {
 				echo "	<tr>\n";
 				echo "		<td class=''>";
@@ -948,7 +948,7 @@
 	echo "	".$text['label-time_base_score_sec']."\n";
 	echo "</td>\n";
 	echo "<td class='vtable' align='left'>\n";
-	echo "  <input class='formfld' type='number' name='queue_time_base_score_sec' maxlength='255' min='0' step='1' value='".escape($queue_time_base_score_sec)."'>\n";
+	echo "  <input class='formfld' type='number' name='queue_time_base_score_sec' maxlength='255' min='0' step='1' value='".escape($queue_time_base_score_sec ?? '')."'>\n";
 	echo "<br />\n";
 	echo $text['description-time_base_score_sec']."\n";
 	echo "</td>\n";
@@ -992,7 +992,7 @@
 	echo "    ".$text['label-timeout_action']."\n";
 	echo "</td>\n";
 	echo "<td class='vtable' align='left'>\n";
-	echo $destination->select('dialplan', 'queue_timeout_action', $queue_timeout_action);
+	echo $destination->select('dialplan', 'queue_timeout_action', !empty($queue_timeout_action));
 	echo "<br />\n";
 	echo $text['description-timeout_action']."\n";
 	echo "</td>\n";
@@ -1121,7 +1121,7 @@
 	echo "	".$text['label-caller_id_name_prefix']."\n";
 	echo "</td>\n";
 	echo "<td class='vtable' align='left'>\n";
-	echo "  <input class='formfld' type='text' name='queue_cid_prefix' maxlength='255' value='".escape($queue_cid_prefix)."'>\n";
+	echo "  <input class='formfld' type='text' name='queue_cid_prefix' maxlength='255' value='".escape($queue_cid_prefix ?? '')."'>\n";
 	echo "<br />\n";
 	echo $text['description-caller_id_name_prefix']."\n";
 	echo "</td>\n";
@@ -1196,8 +1196,8 @@
 		$script .= "	tb.name=obj.name;\n";
 		$script .= "	tb.className='formfld';\n";
 		$script .= "	tb.setAttribute('id', '".$destination_id."');\n";
-		$script .= "	tb.setAttribute('style', '".$select_style."');\n";
-		if ($on_change != '') {
+		$script .= "	tb.setAttribute('style', '".!empty($select_style)."');\n";
+		if (!empty($on_change)) {
 			$script .= "	tb.setAttribute('onchange', \"".$on_change."\");\n";
 			$script .= "	tb.setAttribute('onkeyup', \"".$on_change."\");\n";
 		}
@@ -1221,7 +1221,7 @@
 		$script .= "	obj[0].parentNode.removeChild(obj[1]);\n";
 		$script .= "	obj[0].parentNode.removeChild(obj[2]);\n";
 		$script .= "	document.getElementById('btn_select_to_input_".$destination_id."').style.visibility = 'visible';\n";
-		if ($on_change != '') {
+		if (!empty($on_change)) {
 			$script .= "	".$on_change.";\n";
 		}
 		$script .= "}\n";
@@ -1234,7 +1234,7 @@
 
 		//recordings
 		$tmp_selected = false;
-		if (is_array($recordings)) {
+		if (!empty($recordings)) {
 			echo "<optgroup label='Recordings'>\n";
 			foreach ($recordings as &$row) {
 				$recording_name = $row["recording_name"];
@@ -1287,7 +1287,7 @@
 		echo "  ".$text['label-caller_announce_frequency']."\n";
 		echo "</td>\n";
 		echo "<td class='vtable' align='left'>\n";
-		echo "  <input class='formfld' type='number' name='queue_announce_frequency' maxlength='255' min='0' step='1' value='".escape($queue_announce_frequency)."'>\n";
+		echo "  <input class='formfld' type='number' name='queue_announce_frequency' maxlength='255' min='0' step='1' value='".escape($queue_announce_frequency ?? '')."'>\n";
 		echo "<br />\n";
 		echo $text['description-caller_announce_frequency']."\n";
 		echo "</td>\n";
@@ -1299,7 +1299,7 @@
 	echo "  ".$text['label-exit_keys']."\n";
 	echo "</td>\n";
 	echo "<td class='vtable' align='left'>\n";
-	echo "  <input class='formfld' type='text' name='queue_cc_exit_keys' value='".escape($queue_cc_exit_keys)."'>\n";
+	echo "  <input class='formfld' type='text' name='queue_cc_exit_keys' value='".escape($queue_cc_exit_keys ?? '')."'>\n";
 	echo "<br />\n";
 	echo $text['description-exit_keys']."\n";
 	echo "</td>\n";
@@ -1323,7 +1323,7 @@
 	echo "	".$text['label-description']."\n";
 	echo "</td>\n";
 	echo "<td class='vtable' align='left'>\n";
-	echo "	<input class='formfld' type='text' name='queue_description' maxlength='255' value=\"".escape($queue_description)."\">\n";
+	echo "	<input class='formfld' type='text' name='queue_description' maxlength='255' value=\"".escape($queue_description ?? '')."\">\n";
 	echo "<br />\n";
 	echo $text['description-description']."\n";
 	echo "</td>\n";
diff --git a/app/call_centers/call_center_queues.php b/app/call_centers/call_center_queues.php
index 2677ef1b5a..c97eaf5008 100644
--- a/app/call_centers/call_center_queues.php
+++ b/app/call_centers/call_center_queues.php
@@ -46,15 +46,18 @@
 	$language = new text;
 	$text = $language->get();
 
+//set from session variables
+	$list_row_edit_button = !empty($_SESSION['theme']['list_row_edit_button']['boolean']) ? $_SESSION['theme']['list_row_edit_button']['boolean'] : 'false';
+
 //get posted data
-	if (is_array($_POST['call_center_queues'])) {
+	if (!empty($_POST['call_center_queues'])) {
 		$action = $_POST['action'];
 		$search = $_POST['search'];
 		$call_center_queues = $_POST['call_center_queues'];
 	}
 
 //process the http post data by action
-	if ($action != '' && is_array($call_center_queues) && @sizeof($call_center_queues) != 0) {
+	if (!empty($action) && !empty($call_center_queues)) {
 		switch ($action) {
 			case 'copy':
 				if (permission_exists('call_center_queue_add')) {
@@ -75,11 +78,11 @@
 	}
 
 //get http variables and set as php variables
-	$order_by = $_GET["order_by"];
-	$order = $_GET["order"];
+	$order_by = $_GET["order_by"] ?? '';
+	$order = $_GET["order"] ?? '';
 
 //add the search term
-	$search = strtolower($_GET["search"]);
+	$search = strtolower($_GET["search"] ?? '');
 	if (!empty($search)) {
 		$sql_search = " (";
 		$sql_search .= "lower(queue_name) like :search ";
@@ -91,23 +94,23 @@
 //get total call center queues count from the database
 	$sql = "select count(*) from v_call_center_queues ";
 	$sql .= "where true ";
-	if ($_GET['show'] != "all" || !permission_exists('call_center_all')) {
+	if (!empty($_GET['show']) != "all" || !permission_exists('call_center_all')) {
 		$sql .= "and (domain_uuid = :domain_uuid or domain_uuid is null) ";
 		$parameters['domain_uuid'] = $_SESSION['domain_uuid'];
 	}
-	if (isset($sql_search)) {
+	if (!empty($sql_search)) {
 		$sql .= "and ".$sql_search;
 	}
 	$database = new database;
-	$num_rows = $database->select($sql, $parameters, 'column');
+	$num_rows = $database->select($sql, $parameters ?? null, 'column');
 
 //prepare to page the results
 	$rows_per_page = ($_SESSION['domain']['paging']['numeric'] != '') ? $_SESSION['domain']['paging']['numeric'] : 50;
 	$param = "&search=".urlencode($search);
-	if ($_GET['show'] == "all" && permission_exists('call_center_all')) {
+	if (!empty($_GET['show']) == "all" && permission_exists('call_center_all')) {
 		$param .= "&show=all";
 	}
-	$page = $_GET['page'];
+	$page = $_GET['page'] ?? '';
 	if (empty($page)) { $page = 0; $_GET['page'] = 0; }
 	list($paging_controls, $rows_per_page) = paging($num_rows, $param, $rows_per_page);
 	list($paging_controls_mini, $rows_per_page) = paging($num_rows, $param, $rows_per_page, true);
@@ -118,7 +121,7 @@
 	$sql .= order_by($order_by, $order, 'queue_name', 'asc');
 	$sql .= limit_offset($rows_per_page, $offset);
 	$database = new database;
-	$result = $database->select($sql, $parameters, 'all');
+	$result = $database->select($sql, $parameters ?? null, 'all');
 	unset($sql, $parameters);
 
 //create token
@@ -143,21 +146,21 @@
 		echo button::create(['type'=>'button','label'=>$text['button-wallboard'],'icon'=>'th','link'=>PROJECT_PATH.'/app/call_center_wallboard/call_center_wallboard.php']);
 	}
 	$margin_left = permission_exists('call_center_agent_view') || permission_exists('call_center_wallboard') ? 'margin-left: 15px;' : null;
-	if (permission_exists('call_center_queue_add') && (!is_numeric($_SESSION['limit']['call_center_queues']['numeric']) || $num_rows <= $_SESSION['limit']['call_center_queues']['numeric'])) {
+	if (permission_exists('call_center_queue_add') && (!is_numeric($_SESSION['limit']['call_center_queues']['numeric'] ?? '') || $num_rows <= $_SESSION['limit']['call_center_queues']['numeric'])) {
 		echo button::create(['type'=>'button','label'=>$text['button-add'],'icon'=>$_SESSION['theme']['button_icon_add'],'id'=>'btn_add','style'=>$margin_left,'link'=>'call_center_queue_edit.php']);
 		unset($margin_left);
 	}
-	if (permission_exists('call_center_queue_add') && $result && (!is_numeric($_SESSION['limit']['call_center_queues']['numeric']) || $num_rows <= $_SESSION['limit']['call_center_queues']['numeric'])) {
-		echo button::create(['type'=>'button','label'=>$text['button-copy'],'icon'=>$_SESSION['theme']['button_icon_copy'],'id'=>'btn_copy','name'=>'btn_copy','style'=>'display: none; '.$margin_left,'onclick'=>"modal_open('modal-copy','btn_copy');"]);
+	if (permission_exists('call_center_queue_add') && $result && (!is_numeric($_SESSION['limit']['call_center_queues']['numeric'] ?? '') || $num_rows <= $_SESSION['limit']['call_center_queues']['numeric'])) {
+		echo button::create(['type'=>'button','label'=>$text['button-copy'],'icon'=>$_SESSION['theme']['button_icon_copy'],'id'=>'btn_copy','name'=>'btn_copy','style'=>'display: none; '.!empty($margin_left),'onclick'=>"modal_open('modal-copy','btn_copy');"]);
 		unset($margin_left);
 	}
 	if (permission_exists('call_center_queue_delete') && $result) {
-		echo button::create(['type'=>'button','label'=>$text['button-delete'],'icon'=>$_SESSION['theme']['button_icon_delete'],'id'=>'btn_delete','name'=>'btn_delete','style'=>'display: none; '.$margin_left,'onclick'=>"modal_open('modal-delete','btn_delete');"]);
+		echo button::create(['type'=>'button','label'=>$text['button-delete'],'icon'=>$_SESSION['theme']['button_icon_delete'],'id'=>'btn_delete','name'=>'btn_delete','style'=>'display: none; '.!empty($margin_left),'onclick'=>"modal_open('modal-delete','btn_delete');"]);
 		unset($margin_left);
 	}
 	echo 		"<form id='form_search' class='inline' method='get'>\n";
 	if (permission_exists('call_center_all')) {
-		if ($_GET['show'] == 'all') {
+		if (!empty($_GET['show']) == 'all') {
 			echo "		<input type='hidden' name='show' value='all'>";
 		}
 		else {
@@ -175,7 +178,7 @@
 	echo "	<div style='clear: both;'></div>\n";
 	echo "</div>\n";
 
-	if (permission_exists('call_center_queue_add') && $result && (!is_numeric($_SESSION['limit']['call_center_queues']['numeric']) || $num_rows <= $_SESSION['limit']['call_center_queues']['numeric'])) {
+	if (permission_exists('call_center_queue_add') && $result && (!is_numeric($_SESSION['limit']['call_center_queues']['numeric'] ?? '') || $num_rows <= $_SESSION['limit']['call_center_queues']['numeric'])) {
 		echo modal::create(['id'=>'modal-copy','type'=>'copy','actions'=>button::create(['type'=>'button','label'=>$text['button-continue'],'icon'=>'check','id'=>'btn_copy','style'=>'float: right; margin-left: 15px;','collapse'=>'never','onclick'=>"modal_close(); list_action_set('copy'); list_form_submit('form_list');"])]);
 	}
 	if (permission_exists('call_center_queue_delete') && $result) {
@@ -193,10 +196,10 @@
 	echo "<tr class='list-header'>\n";
 	if (permission_exists('call_center_queue_add') || permission_exists('call_center_queue_delete')) {
 		echo "	<th class='checkbox'>\n";
-		echo "		<input type='checkbox' id='checkbox_all' name='checkbox_all' onclick='list_all_toggle(); checkbox_on_change(this);' ".($result ?: "style='visibility: hidden;'").">\n";
+		echo "		<input type='checkbox' id='checkbox_all' name='checkbox_all' onclick='list_all_toggle(); checkbox_on_change(this);' ".(!empty($result) ?: "style='visibility: hidden;'").">\n";
 		echo "	</th>\n";
 	}
-	if ($_GET['show'] == "all" && permission_exists('call_center_all')) {
+	if (!empty($_GET['show']) == "all" && permission_exists('call_center_all')) {
 		echo th_order_by('domain_name', $text['label-domain'], $order_by, $order, $param, "class='shrink'");
 	}
 	echo th_order_by('queue_name', $text['label-queue_name'], $order_by, $order);
@@ -215,12 +218,12 @@
 	//echo th_order_by('queue_abandoned_resume_allowed', $text['label-abandoned_resume_allowed'], $order_by, $order);
 	//echo th_order_by('queue_tier_rule_wait_multiply_level', $text['label-tier_rule_wait_multiply_level'], $order_by, $order);
 	echo th_order_by('queue_description', $text['label-description'], $order_by, $order, null, "class='hide-sm-dn'");
-	if (permission_exists('call_center_queue_edit') && $_SESSION['theme']['list_row_edit_button']['boolean'] == 'true') {
+	if (permission_exists('call_center_queue_edit') && $list_row_edit_button == 'true') {
 		echo "	<td class='action-button'>&nbsp;</td>\n";
 	}
 	echo "</tr>\n";
 
-	if (is_array($result)) {
+	if (!empty($result)) {
 		$x = 0;
 		foreach($result as $row) {
 			if (permission_exists('call_center_queue_edit')) {
@@ -233,7 +236,7 @@
 				echo "		<input type='hidden' name='call_center_queues[$x][uuid]' value='".escape($row['call_center_queue_uuid'])."' />\n";
 				echo "	</td>\n";
 			}
-			if ($_GET['show'] == "all" && permission_exists('call_center_all')) {
+			if (!empty($_GET['show']) == "all" && permission_exists('call_center_all')) {
 				if (!empty($_SESSION['domains'][$row['domain_uuid']]['domain_name'])) {
 					$domain = $_SESSION['domains'][$row['domain_uuid']]['domain_name'];
 				}
@@ -265,7 +268,7 @@
 			//echo "	<td>".escape($row[queue_abandoned_resume_allowed])."&nbsp;</td>\n";
 			//echo "	<td>".escape($row[queue_tier_rule_wait_multiply_level])."&nbsp;</td>\n";
 			echo "	<td class='description overflow hide-sm-dn'>".escape($row['queue_description'])."</td>\n";
-			if (permission_exists('call_center_queue_edit') && $_SESSION['theme']['list_row_edit_button']['boolean'] == 'true') {
+			if (permission_exists('call_center_queue_edit') && $list_row_edit_button == 'true') {
 				echo "	<td class='action-button'>";
 				echo button::create(['type'=>'button','title'=>$text['button-edit'],'icon'=>$_SESSION['theme']['button_icon_edit'],'link'=>$list_row_url]);
 				echo "	</td>\n";