How to Find out the Version of IE using JavaScript?

This Java function helps to Findout the Version IE Installed in your system
function getIEVersionNumber()
{
var ua = navigator.userAgent;
var MSIEOffset = ua.indexOf("MSIE ");

if (MSIEOffset == -1)
{
return 0;
}
else {
return parseFloat(ua.substring(MSIEOffset + 5, ua.indexOf(";", MSIEOffset)));
}
}