function openPopup(url,w,h) {
var winl = (screen.width - w) / 2;
var wint = (screen.height - h) / 2;
  popupwin=window.open(url, 'popupwin', 'width='+w+',height='+h+',scrollbars=no,toolbar=no,left='+winl+',top='+wint+',screenX='+winl+',screenY='+wint+',resizable=yes,alwaysRaised=yes');
  popupwin.focus();
}