var browser_version = 0;
var browser_name;
if (/MSIE (\d+\.\d+);/.test(navigator.userAgent)){ //test for MSIE x.x;
 browser_name = "IE";
 var ieversion=new Number(RegExp.$1) // capture x.x portion and store as a number
 if (ieversion>=8)
  browser_version = 8;
 else if (ieversion>=7)
  browser_version = 7;
 else if (ieversion>=6)
  browser_version = 6;
 else if (ieversion>=5)
  browser_version = 5;
}