// this function defines constants
function defineNodeConstants() {
  if (!window.Node) {
    window.Node = {
      ELEMENT_NODE: 1,
      ATTRIBUTE_NODE: 2,
      TEXT_NODE: 3,
      COMMENT_NODE: 8,
      DOCUMENT_NODE: 9,
      DOCUMENT_FRAGMENT_NODE: 11
    }
  }
}

function getById(name) {
  var element;
  if (document.getElementById) {
    element = document.getElementById(name);
  } else if (document.all) {
    element = document.all[name];    // Use the all[] array to find the element
  } else if (document.layers) {
    element = document.layers[name]; // Use the layers[] array to get the element
  } else {
    alert("Sorry, I can't play on this browser.");
  }
  return element;
}


function toggleabs(key) {
  var elem = getById("abstext"+key);
  if (elem.className == "visible") {
    elem.className = "invisible";
  } else {
    elem.className = "visible";
  }
}

function togglebib(key) {
  var elem = getById("bibtext"+key);
  if (elem.className == "visible") {
    elem.className = "invisible";
  } else {
    elem.className = "visible";
    window.location = "#top"+key;
  }
}


function toggleallabs() {
  var i;
  var whichway = "";
  var elem = getById("abstext"+abskeys[0]);
  if (elem.className == "visible") {
    whichway = "invisible";
  } else {
    whichway = "visible";
  }
  for (i=0; i<numabs; i++) {
    elem = getById("abstext"+abskeys[i]);
    elem.className = whichway;
  }
}