function checkPost()
{
    var strFehler='';
    if (document.commentform.form_name.value.length<5)
        strFehler += "The entered name is to short! (at least 5 letters!)\n";
    if (document.commentform.form_titel.value.length<5)
        strFehler += "The entered title is to short! (at least 5 letters!)\n";
    if (document.commentform.form_text.value.length<20)
        strFehler += "The entered comment is to short! (at least 20 letters!)\n";
    if (!validEmail(document.commentform.form_email.value)) {
        strFehler += "The entered email is not valid!\n";
    }
    if (strFehler.length>0) {
        alert("There is a problem with your data: \n\n"+strFehler);
        return(false);
    }
}
function validEmail(email)
{
    var strReg = "^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$";
    var regex = new RegExp(strReg);
    return(regex.test(email));
}