function otvor_okno(theURL) { 

  mx = Math.round((screen.width-410)/2);

  my = Math.round((screen.height-510)/2);

  var myWin2=window.open(theURL,"prg","status=yes,toolbar=no,directories=no,scrollbars=yes,location=no,resizable=yes,menubar=no,left="+mx+",top="+my+",width=400,height=500") . focus();

}