window.onload = function() {
	if ( !document.getElementsByTagName ) {
		return false; 
	}
	
	var popuplinks = document.getElementsByTagName("a");
	
	for (var i=0; i < popuplinks.length; i++) {	
		if ( popuplinks[i].getAttribute("class") == "popup" ) {	
			popuplinks[i].onclick = function() {	
				openPopUp( this.getAttribute( "href" ) );
				return false; 	
			} 	
		}
	} 
} 

var popupParams = 'width=337,height=470';

function openPopUp( URL ) {
	window.open( URL, 'popup', popupParams );
}