function $() {
	var aElems = [];
	for (var i=0; i<arguments.length; i++) {
		var soElem = arguments[i];
		if (typeof soElem == 'string') soElem = document.getElementById(soElem);
		if (arguments.length == 1) return soElem;
		aElems.push(soElem);
	}
	return aElems;
}

function RandomHeader(tag, container) {
	this.container = $(container);
	this.items = this.container.getElementsByTagName(tag);
	
	var randNum = Math.floor(Math.random() * (this.items.length));
	for (var i=0, item; item=this.items[i]; i++) {
		if (i==randNum) {
			this.items[i].className = 'active';
		} else {
			this.items[i].className = '';
		}
	}
}

RandomHeader('img', 'randomheader');