function toggleVisibility(elementId)
{
  var toggleElement = document.getElementById(elementId);

  if (toggleElement.style.display == "block")
    toggleElement.style.display = "none";
  else
    toggleElement.style.display = "block";
}

function toggleSubjectVisibility()
{
  var subjectSelect = document.getElementById('subject');
  var pumpReqBlock = document.getElementById('pumprequest');

  // Show or hide the "Pump request" block?
  if (subjectSelect.value == "Aanvraag pomp / nieuwbouw" || subjectSelect.value == "Pump request / newbuilding")
    pumpReqBlock.style.display = "block";
  else
    pumpReqBlock.style.display = "none";
}

function toggleSumpVisibility()
{
  var ele = document.getElementById('sumpdata');

  if (ele.style.display == "none")
    ele.style.display = "";
  else
    ele.style.display = "none";
}

function hideSumpField()
{
  document.getElementById('sumpdata').style.display = "none";
}

function hidePumpRequestBlock()
{
  document.getElementById('pumprequest').style.display = "none";
}