code: function (stateField, histFrame) {
  
              if (_initialized) {
                  // The browser history manager has already been initialized.
                  return;
              }
  
              if (YAHOO.env.ua.opera && typeof history.navigationMode !== "undefined") {
                  // Disable Opera's fast back/forward navigation mode and puts
                  // it in compatible mode. This makes anchor-based history
                  // navigation work after the page has been navigated away
                  // from and re-activated, at the cost of slowing down
                  // back/forward navigation to and from that page.
                  history.navigationMode = "compatible";
              }
  
              if (typeof stateField === "string") {
                  stateField = document.getElementById(stateField);
              }
  
              if (!stateField ||
                  stateField.tagName.toUpperCase() !== "TEXTAREA" &&
                  (stateField.tagName.toUpperCase() !== "INPUT" ||
                   stateField.type !== "hidden" &&
                   stateField.type !== "text")) {
                  throw new Error("Missing or invalid argument");
              }
  
              _stateField = stateField;
  
              // IE < 8 or IE8 in quirks mode or IE7 standards mode
              if (YAHOO.env.ua.ie && (typeof document.documentMode === "undefined" || document.documentMode < 8)) {
  
                  if (typeof histFrame === "string") {
                      histFrame = document.getElementById(histFrame);
                  }
  
                  if (!histFrame || histFrame.tagName.toUpperCase() !== "IFRAME") {
                      throw new Error("Missing or invalid argument");
                  }
  
                  _histFrame = histFrame;
              }
  
              // Note that the event utility MUST be included inline in the page.
              // If it gets loaded later (which you may want to do to improve the
              // loading speed of your site), the onDOMReady event never fires,
              // and the history library never gets fully initialized.
              YAHOO.util.Event.onDOMReady(_initialize);
          }
docs: Initializes the Browser History Manager. Call this method
  from a script block located right after the opening body tag.
  
  @method initialize
  @param {string|HTML Element} stateField <input type="hidden"> used
  to store application states. Must be in the static markup.
  @param {string|HTML Element} histFrame IFrame used to store
  the history (only required on Internet Explorer)
  @public