matchesSelector.js

Element.prototype.matchesSelector || (Element.prototype.matchesSelector = Element.prototype.webkitMatchesSelector || Element.prototype.mozMatchesSelector || function(selecta) {
    var els = document.querySelectorAll(selecta);
    for ( var i=0, L=els.length; i<L; i++ ) {
        if ( els[i] == this ) {
            return true;
        }
    }
    return false;
});