Detecting versions of IE

var ie = (function(){

 

    var undef,

        v = 3,

        div = document.createElement('div'),

        all = div.getElementsByTagName('i');

    

    while (

        div.innerHTML = '<!--[if gt IE ' + (++v) + ']><i></i><![endif]-->',

        all[0]

    );

    

    return v > 4 ? v : undef;

    

}());

 

awsome