detect hovering in js

detecthover.js

(function() {
    var matchfunc = null, prefixes = ["","ms","moz","webkit","o"], i, m;
    for(i=0; i<prefixes.length; i++) {
        m = prefixes[i]+(prefixes[i] ? "Matches" : "matches");
        if( document.documentElement[m]) {matchfunc = m; break;}
        m += "Selector";
        if( document.documentElement[m]) {matchfunc = m; break;}
    }
    if( matchfunc) window.isHover = function(elem) {return elem[matchfunc](":hover");};
    else {
        window.onmouseover = function(e) {
            e = e || window.event;
            var t = e.srcElement || e.target;
            while(t) {
                t.hovering = true;
                t = t.parentNode;
            }
        };
        window.onmouseout = function(e) {
            e = e || window.event;
            var t = e.srcElement || e.target;
            while(t) {
                t.hovering = false;
                t = t.parentNode;
            }
        };
        window.isHover = function(elem) {return elem.hovering;};
   }
})();