function npvd_show(textnapovedy) {
document.getElementById('napoveda').innerHTML = "" + textnapovedy + ""; }

function npvd_clear() {
document.getElementById('napoveda').innerHTML = "Ťukni na logo"; }

function zkontroluj(formular)
{
       if (formular.anspm.value!="5")
    {
        alert("Tady někdo neumí počítat :)");
        formular.anspm.focus();
        return false;
    }	

	if (formular.jmeno.value=="")
    {
        alert("Vaše jméno (přezdívku) musíte vyplnit!");
        formular.jmeno.focus();
        return false;
    }
   /* else if (formular.email.value=="")
    {
        alert("Adresu elektronické pošty musíte vyplnit!");
        formular.email.focus();
        return false;
    }*/
	else if (formular.zprava.value=="")
    {
        alert("Text zprávy musíte vyplnit!");
        formular.zprava.focus();
        return false;
    }
/*	else if (window.RegExp)
    {
        re = new RegExp("^[^.]+(\.[^.]+)*@([^.]+[.])+[a-z]{2,3}$");
        if (!re.test(formular.email.value))
        {
            alert("Zadaná adresa není správnou adresou elektronické pošty!");
            formular.email.focus();
            return false;
        }
    }*/
    else 
        return true;
}


function wopen(url, name, w, h)
{
  // Fudge factors for window decoration space.
  // In my tests these work well on all platforms & browsers.
  w += 32;
  h += 96;
  wleft = (screen.width - w) / 2;
  wtop = (screen.height - h) / 2;
  // IE5 and other old browsers might allow a window that is
  // partially offscreen or wider than the screen. Fix that.
  // (Newer browsers fix this for us, but let's be thorough.)
  if (wleft < 0) {
    w = screen.width;
    wleft = 0;
  }
  if (wtop < 0) {
    h = screen.height;
    wtop = 0;
  }
  var win = window.open(url,
    name,
    'width=' + w + ', height=' + h + ', ' +
    'left=' + wleft + ', top=' + wtop + ', ' +
    'location=no, menubar=no, ' +
    'status=no, toolbar=no, scrollbars=no, resizable=no');
  // Just in case width and height are ignored
  win.resizeTo(w, h);
  // Just in case left and top are ignored
  win.moveTo(wleft, wtop);
  win.focus();
}