function NieuwVenster(URL, Naam, kenmerken)
  {
    NewWindow=window.open(URL, Naam, kenmerken);
    NewWindow.window.focus();
  }

  function checkForm()
  {
    var checkPoints = 0;
    var errorMsg = "Het formulier kan niet worden verzonden worden\n\nControleer de volgende velden:\n\n";
    
    for (i=0;i<document.forms[0].length; i++)
    {
      if (document.forms[0].elements[i].name!="Telefoon" && document.forms[0].elements[i].name!="Opmerking" && document.forms[0].elements[i].name!="Opmerking")
      {
        formElem = document.forms[0].elements[i];
        if (document.forms[0].elements[i].name.substr(0,5)=='Show[')
          checkPoints++
        else
        {
          if (formElem.value.length>0) checkPoints++;
          else errorMsg += "- "+ formElem.name + "\n";
        }
      }
    }
    if (checkPoints!=document.forms[0].length-2)
    {
      alert(errorMsg);
      return false;
    }
    else
      return(true);
  }