How to Check Browser Version

function checkBrowser()

{

var version = 999; // we assume a sane browser

if (navigator.appVersion.indexOf("MSIE") != -1)

version =parseFloat(navigator.appVersion.split("MSIE")[0]);

   // return version;

//    alert(version);

if(version < 8.0)

{

alert(version);

}

document.getElementById("a2").style.width = '150px';

   // alert(window.navigator.appVersion);

}