function hoverin(e, clsname)
{
    if (-1 == e.className.indexOf(clsname)) {
        e.className += ' ' + clsname;
    } 
}

function hoverout(e, clsname)
{
    e.className = e.className.replace(' ' + clsname, '');
}

function nums_only(e)
{
    switch (e.keyCode) {
        case 8:
        case 9:
        case 13:
            return true;
            break;
    }

    k = (e.which) ? e.which : e.keyCode;
    var r = !((k < 48 || k > 57) && (k < 35 || k > 40));

    return r;
}

function objCheck(cinnost, names, ids)
{
    var tmp;

    for (var i = 0; i < ids.length; i++) {
        tmp = document.getElementById(ids[i]);

        if (!tmp.value) {
            var pole = (names[i]) ? names[i] : ids[i];
            var cin  = (cinnost[i]) ? cinnost[i] : 'Zadejte';

            alert(cin + ' prosím ' + pole + '.');

            return false;
        } else if (ids[i].indexOf('email') != -1) {
            var valid = emailCheck(document.getElementById(ids[i]).value);

            if (!valid) {
                return false;
            }
        }
    }

    return true;
}

/// Kontrola správnosti zadání emailové adresy
function emailCheck(email) {
    if (window.RegExp) {
        re = new RegExp("^[_a-zA-Z0-9\-]+(\.[_a-zA-Z0-9-]+)*@[a-zA-Z0-9\-]+(\.[a-zA-Z0-9\-]+)*\.[a-zA-Z]{2,6}$");

        if (!re.test(email)) {
            window.alert("Emailová adresa nemá správný formát!");
            return false;
        }
    }

    return true;
}