if (/MSIE (\d+\.\d+);/.test(navigator.userAgent)){ //test for MSIE x.x;
 var ieversion=new Number(RegExp.$1) // capture x.x portion and store as a number
 if (ieversion<=6)
 window.location="http://fastsite.ro/pb/browser/browser.php";
 else if (ieversion<=5)
  window.location="http://fastsite.ro/pb/browser/browser.php";
}