ById(id);
	    if (elem) {
	        if(/^iframe$/i.test(elem.tagName)) return id; //Frame, OK
	        // else: Look for frame
	        var elems = elem.getElementsByTagName("iframe");
	        if (!elems.length) return null; //No iframe found, FAILURE
	        for (var i=0; i<elems.length; i++) {
	           if (/^https?:\/\/(?:www\.)?youtube(?:-nocookie)?\.com(\/|$)/i.test(elems[i].src)) break;
	        }
	        elem = elems[i]; //The only, or the best iFrame
	        if (elem.id) return elem.id; //Exis