function zkontroluj1(formular, langalert)
{
	if (formular.datum_nastupu.value=="")
    {
        alert(langalert);
        formular.datum_nastupu.focus();
        return false;
    }
	else if (formular.datum_odjezdu.value=="")
    {
        alert(langalert);
        formular.datum_odjezdu.focus();
        return false;
    }
    else
        return true;
}


function zkontroluj2(formular, langalert)
{
	if (formular.jmeno.value=="")
    {
        alert(langalert);
        formular.jmeno.focus();
        return false;
    }
	else if (formular.narodnost.value=="")
    {
        alert(langalert);
        formular.narodnost.focus();
        return false;
    }
	else if (formular.email.value=="" && formular.telefon.value=="")
    {
        alert(langalert);
        formular.email.focus();
        return false;
    }
    else
        return true;
}