function popup_window (winname, x, y, w, h, pathstr) {
  wpop = open('', winname, "width="+w+",height="+h+",status=no,toolbar=no,menubar=no,resizable=yes, scrollbars=yes");
  wpop.location = 'popup.php?' + pathstr;
  if ((x != 0) || (y != 0)) {
    wpop.moveTo(x, y);
  }
  wpop.focus();
  if (window.opener != null) {
    wpop.opener = window.opener;
  }
}

function digit_pressed () {
  if ((event.keyCode < 48) || (event.keyCode > 57)) {return false;} else {return true;}
}