var ntsc;
var msie;

   if  (navigator.appName == "Microsoft Internet Explorer")
   {
       if  (navigator.appVersion.substring(0,1) >= 4 )
       {   msie = true;
           var dokument = 'document.all.';
           var layername = null;
           var stil = '.style';
           var oben = '.pixelTop';
           var links = '.pixelLeft';
       }
   }

   else
   {
            ntsc = true;
            var dokument = 'document.layers.';
            var stil = '';
            var layername = '';
   }