function display(pagename,wd,ht) {

	if(!ht){
		var ht = 500;}
	if(!wd){
		var wd = 530;}

	tp = (screen.availHeight - ht) / 2;
	lt = (screen.availWidth - wd) / 2;

	features = 'height=' + ht.toString() + ',width=' + wd.toString() + ',top=' + tp.toString() + ',left=' + lt.toString() + ',location=no,menubar=no,directories=no,toolbar=no,status=yes,titlebar=yes,resizable=no,scrollbars=yes';
	window.open(pagename, '', features);

}