if( navigator.appName != "Microsoft Internet Explorer" )
   {   //alert("Fenterbreite = " + window.outerWidth);
       if( window.outerWidth <= 850&& window.outerWidth > 690 )
       {
         css = "800";
       }
       if( window.outerWidth <= 1074 && window.outerWidth > 850 )
       {
         css = "1024";
       }
       if( window.outerWidth <= 1330 && window.outerWidth > 1074 )
       {
         css = "1280";
       }
       if( window.outerWidth <= 1650 && window.outerWidth > 1330 )
       {
         css = "1600";
       }
       if( window.outerWidth <= 1970 && window.outerWidth > 1650 )
       {
         css = "1920";
       } 
        
       document.write ('<link rel=stylesheet type="text/css" href="css/bg' + css + '.css">');
   }  
   else
   {   //alert("Fenterbreite = " + screen.Width);
       if( screen.Width <= 850&& screen.Width > 690 )
       {
         css = "800";
       }
       if( screen.Width <= 1274 && screen.Width > 850 )
       {
         css = "1024";
       }
       if( screen.Width <= 1330 && screen.Width > 1074 )
       {
         css = "1280";
       }
       if( screen.Width <= 1650 && screen.Width > 1330 )
       {
         css = "1600";
       }
       if( screen.Width <= 1970 && screen.Width > 1650 )
       {
         css = "1920";
       } 

       document.write ('<link rel=stylesheet type="text/css" href="css/bg' + css + '.css">');
   }