function dropdown_validator()
{

if (dropdown_form.naam.value == "")
{
alert("Vul uw naam in!");
dropdown_form.naam.focus();
return (false);
}

if (dropdown_form.email.value == "" || dropdown_form.email.value.indexOf('@', 0) == -1)
{
alert("Vul uw e-mailadres correct in!");
dropdown_form.email.focus();
return (false);
}

if (dropdown_form.bericht.value == "")
{
alert("Vul uw bericht in!");
dropdown_form.bericht.focus();
return (false);
}

return (true);
}