diff --git a/build/api/module/casController.php b/build/api/module/casController.php
index 9b1b281..2667d27 100644
--- a/build/api/module/casController.php
+++ b/build/api/module/casController.php
@@ -48,7 +48,7 @@ class casController{
 		/* (0) Global DOWNLOAD data
 		---------------------------------------------------------*/
 		$headers = ['Content-Type' => 'text/html; charset=UTF-8' ];
-		$body_start = "Veuillez patienter...<br>Vous allez être redirigés<script type='text/javascript'>window.opener.cas_callback(";
+		$body_start = "Veuillez patienter...<br>Vous allez être redirigés<script type='text/javascript'>( typeof window.opener.cas_callback === 'function' ) && window.opener.cas_callback(";
 		$body_end = ");window.close();</script>";
 
 
diff --git a/webpack/data/login.js b/webpack/data/login.js
index 358a83c..3311bf9 100644
--- a/webpack/data/login.js
+++ b/webpack/data/login.js
@@ -1,11 +1,25 @@
+gstore.add('popup_opened', false);
+
 gstore.add('popup_click', function(){
 
-	/* (1) Open popup */
+	/* (1) Do nothing if already opened */
+	if( gstore.get.popup_opened )
+		return;
+
+	/* (2) Store that popup is opened */
+	gstore.get.popup_opened = true;
+
+	/* (3) Open popup */
 	window.pop = window.open('https://sso.univ-pau.fr/cas/login?service='+window.api.target+'cas', '_blank', 'location=no,height=1024,width=1024,scrollbars=yes,status=no');
 
-	/* (2) If popup closed -> abort */
+	/* (4) Clear interval (optional) */
+	!isNaN(window.popint) && clearInterval(window.popint);
+
+	/* (5) Check if popup closed -> abort */
 	window.popint = setInterval(function(){ window.pop.closed && window.cas_callback(null); }, 500);
 
+
+
 });
 
 gstore.add('login_class', 'neutral');
diff --git a/webpack/page/login.js b/webpack/page/login.js
index c7833de..9327d76 100644
--- a/webpack/page/login.js
+++ b/webpack/page/login.js
@@ -32,11 +32,11 @@ window.cas_callback = function(cas_login){
 	setTimeout( function(){ if( window.pop.closed ){
 
 		/* (2) Stop interval that checks if window closed */
-		clearInterval(window.popint);
-
+		!isNaN(window.popint) && clearInterval(window.popint);
 
 		/* (3) If no login -> error */
 		if( cas_login === null ){
+
 			gstore.get.login_error_text = 'Erreur de connexion. Veuillez réessayer.';
 			gstore.get.login_class = 'invalid';
 
@@ -47,6 +47,7 @@ window.cas_callback = function(cas_login){
 
 			gstore.get.login_error_text = 'Vous êtes connectés. Vous allez être redirigé.';
 			gstore.get.login_class = 'valid';
+
 			setTimeout(function(){ document.location = '/'; }, 1500);
 
 		}