function loadPopup(popup, url, width, height) {
	var left = (screen.width  - width) / 2 ;
	var top  = (screen.height - height) / 2 ;

	settings = "toolbar=no,status=no,scrollbars=yes,resizable=no,dependent=yes";
	settings += ",width=" + width;
	settings += ",height=" + height;
	settings += ",left=" + left;
	settings += ",top=" + top;
	
	var popup_window = window.open( url, popup, settings ) ;
}