function NewWindow(mypage,myname,w,h,scroll) {
  LeftPosition = (screen.width) ? (screen.width-w)/2 : 0;
  TopPosition = (screen.height) ? (screen.height-h)/2 : 0;
  settings = 'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars='+scroll+',resizable';
  win = window.open(mypage,myname,settings)
}

function checkd(whois) {
  if (whois.domain.value!="") {
    var index = whois.ext.selectedIndex;
    NewWindow('whois.php?domain='+whois.domain.value+'&ext='+whois.ext.options[index].text,'whois','500','500','yes');
    return false;
  }
}