function showhideverzoek()
  {
    if (document.contactformulier.verzoekcheck.checked)
    {
      document.getElementById("verzoekarea").style.display = "block";
    }
    else
    {
      document.getElementById("verzoekarea").style.display = "none";
    }
  }
  function showhidebericht()
  {
    if (document.contactformulier.berichtcheck.checked)
    {
      document.getElementById("berichtarea").style.display = "block";
    }
    else
    {
      document.getElementById("berichtarea").style.display = "none";
    }
  }