var now = new Date();

function okno(adresa,parametry) {
  var okno_jmeno = now.valueOf();
  if (!Boolean(parametry))  parametry = 'width=400,height=500,scrollbars=1';
  oknoDialog = window.open('',okno_jmeno,parametry);
	oknoDialog.location = adresa;
	oknoDialog.focus();  
}