function popup(src_url, w, h) {
  var Okno;
  var aw,ah;
  if( window.screen ) {
    aw=screen.availWidth;
    ah=screen.availHeight;
  } else {
    aw=640;
    ah=480;
  }
  if( w > aw ) w=aw;
  if( h > ah ) h=ah;

/*  if ( Okno != null ) Okno.close(); */
  
  var sets=
    "width=" + w + ","
    + "height=" + h + ","
    + "toolbar=no,"
    + "location=no,"
    + "directories=no,"
    + "status=no,"
    + "menubar=no,"
    + "scrollbars=no,"
    + "copyhistory=no,"
    + "resizable=yes,"
    + "top=50,"
    + "left=50";
  Okno=window.open(src_url, 'popupWindow', sets);
  Okno.focus();
}