function isValidCode ()
{
  var v = GetObjectByRef ("Bevestigingscode");
  if (v == null)
    return true;
  v = v.value;
  return Math.floor (v / 100) % 97 == (v % 100);
}
function isFieldFilled (f)
{
  var o = GetObjectByRef (f);
  return o == null || o.value != "";
}
function isValidEmail (f)
{
  var o = GetObjectByRef (f);
  return o == null || (o.value.indexOf("@") > 0);
}
function isFilled ()
{
  return isValidCode () && isFieldFilled ("Name") && isFieldFilled ("Email");
}
function SetInfo (id, info, valid)
{
  var o = GetObjectByRef (id);
  if (o == null)
    return;
  o.innerHTML = valid ? "": info;
}
function SetInfoNeeded (name, valid)
{
  SetInfo ('Check'+name, "Dit veld is vereist", valid);
  var o = GetObjectByRef (name);
  if (o == null)
    return;
  var cn = GetClassName (o);
  if (valid)
  {
    var pos = cn.indexOf (" Needed");
    if (pos >= 0)
    {
	    cn = cn.substr (0, cn);
	    SetClassName (o, cn);
	  } // if 
  }
  else
  {
    var pos = cn.indexOf (" Needed");
    if (pos < 0)
    {
      SetClassName (o, cn + " Needed");
    } // if 
  } // if
}

function checkCode (obj)
{
  var validCode = isValidCode ();
  var validNaam = isFieldFilled ("Naam");
  var validAdres = isFieldFilled ("Adres");
  var validGemeente = isFieldFilled ("Gemeente");
  var validTelefoon = isFieldFilled ("Telefoon");
  var validEmail = isValidEmail ("Email");
  var validSecCode = isFieldFilled ("Code");
  
  SetInfo ("CheckBevestigingscode", "Dit is een ongeldige code", validCode);
  SetInfoNeeded ("Naam", validNaam);
  SetInfoNeeded ("Adres", validAdres);
  SetInfoNeeded ("Gemeente", validGemeente);
  SetInfoNeeded ("Telefoon", validTelefoon);
  SetInfoNeeded ("Email", validEmail);
  SetInfoNeeded ("Code", validSecCode);
  var o = GetObjectByRef ("Send");
  if (o != null)
    o.style.display= isFilled () ? "inline" : "none";
    
  var submit = GetObjectByRef ("SubmitButton");
  if (submit !== null)
    submit.disabled = !validCode || !validNaam || !validAdres || !validGemeente || !validTelefoon || !validEmail || !validSecCode;
}