IE version check From:http://snipplr.com/view.php?codeview&id=71705#

checkIE.js

//IE VERSION CONTROL
function getInternetExplorerVersion() {
  // Return value assumes failure.
  var rv = -1; 

	if (navigator.appName == 'Microsoft Internet Explorer') {
		var ua = navigator.userAgent;
		var re = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
		if (re.exec(ua) != null) rv = parseFloat(RegExp.$1);
	}
	return rv;
}