gistfile1.js

// ----------------------------------------------------------
// A short snippet for detecting versions of IE in JavaScript
// without resorting to user-agent sniffing
// ----------------------------------------------------------
// If you're not in IE (or IE version is less than 5) then:
//     ie === undefined
// If you're in IE (>=5) then you can determine which version:
//     ie === 7; // IE7
// Thus, to detect IE:
//     if (ie) {}
// And to detect the version:
//     ie === 6 // IE6
//     ie > 7 // IE8, IE9 ..., false for non-IE
//     ie < 9 // Any IE less than IE9, false for non-IE
// ----------------------------------------------------------
// Made it JSLint friendly

var ie = (function () {
	var u,
		v = 3,
		b = document.createElement('b'),
		i = b.getElementsByTagName('i');
	do {
		v += 1;
		b.innerHTML = '<!--[if gt IE ' + v + ']><i></i><![endif]-->';
	} while (i[0]);
	return v > 4 ? v : u;
}());