From 859cf4905e2f00e1636f62bfd77206c379a13250 Mon Sep 17 00:00:00 2001
From: Mario Stephan <mstephan@shared-files.de>
Date: Tue, 17 Mar 2015 21:09:50 +0100
Subject: [PATCH] Added an extra check for null for button states

---
 js/fhem-tablet-ui.js | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/js/fhem-tablet-ui.js b/js/fhem-tablet-ui.js
index f06abd0c..56f4eba5 100755
--- a/js/fhem-tablet-ui.js
+++ b/js/fhem-tablet-ui.js
@@ -369,15 +369,16 @@ function update(filter) {
 	 	else if (deviceType == 'switch' || deviceType == 'contact'){
 			
 			var state = getDeviceValue( $(this), 'get' );
-			
-			if ( state == $(this).data('get-on') )
-				$(this).data('famultibutton').setOn();
-			else if ( state == $(this).data('get-off') )
-				$(this).data('famultibutton').setOff();
-	 		else if ( state.match(RegExp('^' + $(this).data('get-on') + '$')) )
-			    	$(this).data('famultibutton').setOn();
-			else if ( state.match(RegExp('^' + $(this).data('get-off') + '$')) )
-			    	$(this).data('famultibutton').setOff();
+			if (state) {
+				if ( state == $(this).data('get-on') )
+					$(this).data('famultibutton').setOn();
+				else if ( state == $(this).data('get-off') )
+					$(this).data('famultibutton').setOff();
+				else if ( state.match(RegExp('^' + $(this).data('get-on') + '$')) )
+						$(this).data('famultibutton').setOn();
+				else if ( state.match(RegExp('^' + $(this).data('get-off') + '$')) )
+						$(this).data('famultibutton').setOff();
+			}
 		}
  	});
  	ready = true;