function ValidateEmail(emailad)
    {
      var re = /^[_a-zA-Z0-9\-\_\.\+&]+(\.[_a-zA-A0-9\-\_\.\+&]+)*@[a-zA-Z0-9-\.]+(\.[a-zA-Z-9\-\.]+)*(\.[a-zA-Z]{2,4})$/;
      if (re.test(emailad))
      {
        return true;
      } else
      {
        return false;
      }
    }

    function CheckNewsletterForm()
    {
      frmCheck = document.frmNewsletter;

      res = true;

      if (!ValidateEmail(frmCheck.email.value))
      {
        window.alert("Dit is geen geldig e-mailadrs");
        frmCheck.email.focus();
        res = false;
      }

      return res;
    }