matchesSelector Polyfill // returns whether an element matches a selector

matchesSelector.polyfill.js

this.Element && function(ElementPrototype) {
	ElementPrototype.matchesSelector = ElementPrototype.matchesSelector || 
	ElementPrototype.mozMatchesSelector ||
	ElementPrototype.msMatchesSelector ||
	ElementPrototype.oMatchesSelector ||
	ElementPrototype.webkitMatchesSelector ||
	function (selector) {
		var node = this, nodes = (node.parentNode || node.document).querySelectorAll(selector), i = -1;

		while (nodes[++i] && nodes[i] != node);

		return !!nodes[i];
	}
}(Element.prototype);

matchesSelector.polyfill.min.js

this.Element&&function(e){e.matchesSelector=e.matchesSelector||e.mozMatchesSelector||e.msMatchesSelector||e.oMatchesSelector||e.webkitMatchesSelector||function(e){var t=this,n=(t.parentNode||t.document).querySelectorAll(e),r=-1;while(n[++r]&&n[r]!=t);return!!n[r]}}(Element.prototype)