function openLayer(layerID, text) {
  document.getElementById('openLayer_' + layerID).style.display = "block";
  document.getElementById('closedLayer_' + layerID).innerHTML="<a href=\"javascript:closeLayer('" + layerID + "', '" + text + "');\">" + text + "</a>";
}
function closeLayer(layerID, text) {
  document.getElementById('openLayer_' + layerID).style.display = "none";
  document.getElementById('closedLayer_' + layerID).innerHTML="<a href=\"javascript:openLayer('" + layerID + "', '" + text + "');\">" + text + "</a>";
}