function checkEmail(email)
{
    var filter=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i;
    return filter.test(email);
}

function checkContent(what,language)
{
    // 1...de, 2...en
    var form;
    if (what == "contact" || what == "contact_left")
    {
        form = document.contactform;
    }
    else if (what == "newsletter")
    {
        form = document.newsletterform;
    }
    else if (what == "download")
    {
        form = document.downloadform;
    }
    else if (what == "fairticket")
    {
        form = document.fairticketform;
    }
    else
    {
        alert("Unknown form to check: " + what);
        return false;
    }
     
    if ((what == "contact" || what == "contact_left" || what == "download" || what == "fairticket") && form.firstname.value == "")
    {
        if (language == 1)
        {
            alert("Bitte geben Sie Ihren Vornamen an.");
        }
        else
        {
            alert("Please fill in your firstname.");
        }
        form.firstname.focus();
        return false;
    }
        
    if ((what == "contact" || what == "contact_left" || what == "download" || what == "fairticket") && form.lastname.value == "")
    {
        if (language == 1)
        {
            alert("Bitte geben Sie Ihren Nachnamen an.");
        }
        else
        {
            alert("Please fill in your lastname.");
        }
        form.lastname.focus();
        return false;
    }
        
    if ((what == "contact" || what == "contact_left" || what == "download" || what == "fairticket") && form.phone.value == "")
    {
        if (language == 1)
        {
            alert("Bitte geben Sie Ihre Telefonnummer an.");
        }
        else
        {
            alert("Please fill in your phone number.");
        }
        form.phone.focus();
        return false;
    }
        
    if ((what == "contact" || what == "contact_left" || what == "newsletter" || what == "download" || what == "fairticket") && form.email.value == "")
    {
        if (language == 1)
        {
            alert("Bitte geben Sie Ihre E-Mail-Adresse an.");
        }
        else
        {
            alert("Please fill in your e-mail address.");
        }
        form.email.focus();
        return false;
    }
        
    if ((what == "contact" || what == "contact_left" || what == "newsletter" || what == "download" || what == "fairticket") && !checkEmail(form.email.value))
    {
        if (language == 1)
        {
            alert("Bitte geben Sie Ihre gültige E-Mail-Adresse an.");
        }
        else
        {
            alert("Please fill in your valid e-mail address.");
        }
        form.email.focus();
        return false;
    }
        
    if ((what == "contact" || what == "contact_left" || what == "download" || what == "fairticket") && form.company.value == "")
    {
        if (language == 1)
        {
            alert("Bitte geben Sie Ihre Firma an.");
        }
        else
        {
            alert("Please fill in your company.");
        }
        form.company.focus();
        return false;
    }
    
    if ((what == "fairticket") && form.address.value == "")
    {
        if (language == 1)
        {
            alert("Bitte geben Sie Ihre Adresse an.");
        }
        else
        {
            alert("Please fill in your address.");
        }
        form.address.focus();
        return false;
    }
    
    if ((what == "fairticket") && !form.wantcards.checked)
    {
        if (language == 1)
        {
            alert("Bitte kreuzen Sie ja an, wenn Sie Karten bestellen wollen.");
        }
        else
        {
            alert("Please commit that you want fair ticktes.");
        }
        form.wantcards.focus();
        return false;
    }
    
    if ((what == "contact") && form.financialContract[1].checked) // 0...no, 1...yes
    {
        if (form.financialContractsAvailable.value == "")
        {
            if (language == 1)
            {
                alert("Bitte geben Sie an, bei welchem Finanzdienstleister bereits Verträge vorhanden sind.");
            }
            else
            {
                alert("Please fill in, where you have your financial service provider contracts.");
            }
            form.financialContractsAvailable.focus();
            return false;
        }
    }
        
    if ((what == "contact" || what == "newsletter" || what == "download" || what == "fairticket") && form.agb.checked != true)
    {
        if (language == 1)
        {
            alert("Bitte bestätigen Sie, dass Sie die AGB und das Privacy Statement gelesen und akzeptiert haben.");
        }
        else
        {
            alert("Please commit that you have read and accepted the GTC/Private Statement.");
        }
        form.agb.focus();
        return false;
    }
    
    return true;
}