// TreeVisible
function TreeVisible( htmlparent, state ) {
  var theSource;
  var theDest;

  if ( state ) {
    theSource = document.getElementById( htmlparent + '-hidden' );
    theDest = document.getElementById( htmlparent );
  }
  else {
    theSource = document.getElementById( htmlparent );
    theDest = document.getElementById( htmlparent + '-hidden' );
  }

  theDest.innerHTML = theSource.innerHTML;
  theSource.innerHTML = '';

  var theToggle = document.getElementById( htmlparent + '-toggle' );

  if ( state ) {
    theToggle.innerHTML = '[-]';
    theToggle.href = "javascript:TreeVisible('" + htmlparent + "', false)";
  }
  else {
    theToggle.innerHTML = '[+]';
    theToggle.href = "javascript:TreeVisible('" + htmlparent + "', true)";
  }
}