var commentForm = false;

function checkForm() {
    var comment = document.getElementsByName("comment")[0];
    var mail = document.getElementsByName("mail")[0];
    var captcha = document.getElementsByName("captcha")[0];
    if (!comment || !mail || !captcha) {
        return true;
    }
    var fail = false;
    mailReg = /^[\w._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/;
    if ((mail.value.search(mailReg) == -1 || mail.value == '@')) {
        document.getElementById("formMail").style.color = "red";
        fail = true;
    }

    if (!comment.value) {
        document.getElementById('formComment').style.color = "red";
        fail = true;
    }
    if (!captcha.value) {
        document.getElementById('formCaptcha').style.color = "red";
        fail = true;
    }
    return !fail;
}