var PopupWindow = Class.create();
PopupWindow.prototype = {
	
	initialize: function(className, parentElement) {
					var elements = document.getElementsByClassName(className, parentElement);
						for (var i = 0, len = elements.length; i < len; i++) {
						Event.observe(elements[i], 'click', this.addPopupEvent.bindAsEventListener(this));
						Event.observe(elements[i], 'keypress', this.addPopupEvent.bindAsEventListener(this));
					}
				},
	addPopupEvent: function(event) {
		var element = Event.element(event);
		var link = element.getAttribute('href');
		window.open(link);
		Event.stop(event);
	}
}; 

Event.observe(window, 'load', function () {
	new PopupWindow('popup');
});

//<a href="foo.html" onclick="window.open('foo.html'); return false;">foo</a> 

/*
<script language="Javascript">
		function openNewWindow(el) { 
			window.open(el.href); 
			return false; 
		} 
	</script>

<a href="foo.html" onclick="return openNewWindow(this);">foo</a>
*/