function molnar_popup(URL,popW, popH, scroll)
{
 var winleft = (screen.width - popW) / 2;
 var winUp = (screen.height - popH) / 2;
 winProp = 'width='+popW+',height='+popH+',left='+winleft+',top='+winUp+',scrollbars='+scroll+'';
 Win = window.open(URL,'edunet_pop', winProp);
}