function getElementsByClass( searchClass, domNode, tagName) {
  if (domNode == null) domNode = document;
  if (tagName == null) tagName = '*';
  var el = new Array();
  var tags = domNode.getElementsByTagName(tagName);
  var tcl = " "+searchClass+" ";
  for(i=0,j=0; i<tags.length; i++) {
    var test = " " + tags[i].className + " ";
    if (test.indexOf(tcl) != -1)
      el[j++] = tags[i];
  }
  return el;
}

function switchMenu(tabname) {
  if ( document.getElementById(tabname).style.display == "block" ) {
    document.getElementById(tabname).style.display = 'none';
  } else {
    var tabs = getElementsByClass('collapsible');
    for(i=0; i<tabs.length; i++)
      tabs[i].style.display = 'none';
      document.getElementById(tabname).style.display = 'block';
  }
}
;