function chkMail() {
    if (document.mailForm.name.value=="") {
        alert(errorNoName);
        document.mailForm.name.focus();
        return false;

    } else if (document.mailForm.email.value=="") {
        alert(errorNoEmail);
        document.mailForm.email.focus();
        return false;       

    } else if (document.mailForm.text.value=="") {
        alert(errorNoText);
        document.mailForm.text.focus();
        return false;       

    } else {
       return true;
    }
}