function popup(link, name, w, h) {

	var loc_top = screen.height/2-h/2-50;
	if (!loc_top) loc_top = 250;

	var loc_left = screen.width/2-w/2;
	if (!loc_left) loc_left = 450;
	
	window.open(link, name, 'width='+w+',height='+h+',left='+loc_left+',top='+loc_top+',scrollbars=no,resizable=no,status=no');
}