function checkDatum() {

  var year = document.getElementById('jaarcheck').value;
  var month = document.getElementById('maandcheck').value;
  var day = document.getElementById('dagcheck').value;

  var band_id = document.getElementById('band_id').value;

  var dateToCheck = new Date();
  dateToCheck.setFullYear(year, month - 1, day);

  var today = new Date();

  if (dateToCheck <= today) {
    alert('Kies een datum in de toekomst');
    document.getElementById('tbl_beschikbaarheid').style.display = 'none';
    return false;
  }

  document.getElementById('row_loading').style.display = 'block';
  document.getElementById('row_ochtend').style.display = 'none';
  document.getElementById('row_middag').style.display = 'none';
  document.getElementById('row_avond').style.display = 'none';
  document.getElementById('row_available').style.display = 'none';
  document.getElementById('row_notavailable').style.display = 'none';
  document.getElementById('tbl_beschikbaarheid').style.display = 'block';

  var dagcheck = document.getElementById('dagcheck');
  var maandcheck = document.getElementById('maandcheck');
  var jaarcheck = document.getElementById('jaarcheck');

  ajaxCheckDatum(band_id);

}

function showResult(daypartsavailable) {

  document.getElementById('row_notavailable').style.display = 'none';
  document.getElementById('row_available').style.display = 'none';

  if (daypartsavailable.indexOf('o') == -1) {
    document.getElementById('span_ochtend').innerHTML = "Niet beschikbaar";
    document.getElementById('img_ochtend').src = "images/iconfout.gif";
  }
  else {
    document.getElementById('span_ochtend').innerHTML = "Beschikbaar";
    document.getElementById('img_ochtend').src = "images/iconok.gif";
  }

  if (daypartsavailable.indexOf('m') == -1) {
    document.getElementById('span_middag').innerHTML = "Niet beschikbaar";
    document.getElementById('img_middag').src = "images/iconfout.gif";
  }
  else {
    document.getElementById('span_middag').innerHTML = "Beschikbaar";
    document.getElementById('img_middag').src = "images/iconok.gif";
  }

  if (daypartsavailable.indexOf('a') == -1) {
    document.getElementById('span_avond').innerHTML = "Niet beschikbaar";
    document.getElementById('img_avond').src = "images/iconfout.gif";
  }
  else {
    document.getElementById('span_avond').innerHTML = "Beschikbaar";
    document.getElementById('img_avond').src = "images/iconok.gif";
  }

  document.getElementById('row_loading').style.display = 'none';
  document.getElementById('row_ochtend').style.display = 'block';
  document.getElementById('row_middag').style.display = 'block';
  document.getElementById('row_avond').style.display = 'block';

  if (daypartsavailable.length > 0) {
    document.getElementById('row_available').style.display = 'block';
  }
  else {
    document.getElementById('row_notavailable').style.display = 'block';
  }
}

function ajaxCheckDatum(id) {

  var dagcheck = document.getElementById('dagcheck');
  var maandcheck = document.getElementById('maandcheck');
  var jaarcheck = document.getElementById('jaarcheck');

  var parID = 'id=' + id;
  var parDag = 'day=' + dagcheck.value;
  var parMaand = 'month=' + maandcheck.value;
  var parJaar = 'year=' + jaarcheck.value;

  var parameters = parID + '&' + parDag + '&' + parMaand + '&' + parJaar;

  var XMLHTTPObject = createHTTPHandler();
  XMLHTTPObject.open('POST', 'http://www.opzoeknaareenband.nl/include/CheckDatum2.php', true);
  XMLHTTPObject.onreadystatechange = function() {
    if (XMLHTTPObject.readyState == 4) {
      showResult(XMLHTTPObject.responseText);
    }
  }

  XMLHTTPObject.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  XMLHTTPObject.setRequestHeader("Content-length", parameters.length);
  //    XMLHTTPObject.setRequestHeader("Connection", "close");
  XMLHTTPObject.setRequestHeader("Cache-Control", "no-cache");
  XMLHTTPObject.setRequestHeader("X_USERAGENT", "MijnAjaxApplicatie");

  XMLHTTPObject.send(parameters);
}