function openWindow(url, name, w, h) {
  var winX = 50;
  var winY = 50;
  if (parseInt(navigator.appVersion) >= 4) {
    winX = (screen.availWidth - w)*.5;
    winY = (screen.availHeight - h)*.25;
  }
  popupWin = window.open(url, name, 'width=' + w + ',height=' + h + ',left=' + winX + ',top=' + winY);
}