facebook browser fix for extjs

gistfile1.txt

var iOS = parseFloat(
      ('' + (/CPU.*OS ([0-9_]{1,5})|(CPU like).*AppleWebKit.*Mobile/i.exec(navigator.userAgent) || [0,''])[1])
         .replace('undefined', '3_2').replace('_', '.').replace('_', '')
   ) || false;

   if ( iOS )
   {
      var userAgent = navigator.userAgent;
      navigator.__defineGetter__('userAgent', function(){

         if ( iOS )
            return userAgent.replace( 'like Gecko) Mobile', 'like Gecko) Version/' + iOS + '.0 Mobile' ) // customized user agent
         else
            return userAgent;
      });
   }