function domReady( f ) {
      // If the DOM is already loaded, execute the function right away
      if ( domReady.done ) return f();
  
      // If we’ve already added a function
      if ( domReady.timer ) {
          // Add it to the list of functions to execute
          domReady.ready.push( f  );
      } else {
          // Attach an event for when the page finishes  loading,
          // just in case it finishes first. Uses addEvent.
          addEvent( window, “load”, isDOMReady );
  
          // Initialize the array of functions to execute
          domReady.ready = [ f ];
  
          //  Check to see if the DOM is ready as quickly as possible
          domReady.timer = setInterval( isDOMReady, 13 );
      }
  }
  
  // Checks to see if the DOM is ready for navigation
  function isDOMReady() {
      // If we already figured out that the page is ready, ignore
      if ( domReady.done ) return false;
  
      // Check to see if a number of functions and elements are
      // able to be accessed
      if ( document && document.getElementsByTagName && 
            document.getElementById && document.body ) {
  
          // If they’re ready, we can stop checking
          clearInterval( domReady.timer );
          domReady.timer = null;
  
          // Execute all the functions that were waiting
          for ( var i = 0; i < domReady.ready.length; i++ )
              domReady.ready[i]();
  
          // Remember that we’re now done
          domReady.ready = null;
          domReady.done = true;
      }
  }