var preloaded = [];

   // here is a lame preloading script i am putting in just for demonstration
   for (var i = 1; i <= 8; i++) {
    preloaded[i] = [loadImage(i + "-0.gif"), loadImage(i + "-1.gif")];
   }

   function init() {
    // whatever stuff you need to do onload goes here.

    //==========================================================================================
    // if supported, initialize mtdropdowns
    //==========================================================================================
    // Check isSupported() so that menus aren't accidentally sent to non-supporting browsers.
    // This is better than server-side checking because it will also catch browsers which would
    // normally support the menus but have javascript disabled.
    //
    // If supported, call initialize() and then hook whatever image rollover code you need to do
    // to the .onactivate and .ondeactivate events for each menu.
    //==========================================================================================
    if (mtDropDown.isSupported()) {
     mtDropDown.initialize();

     // hook all the image swapping of the main toolbar to menu activation/deactivation
     // instead of simple rollover to get the effect where the button stays hightlit until
     // the menu is closed.
     menu1.onactivate = function() { swapImage("button1", preloaded[1][1].src) };
     menu1.ondeactivate = function() { swapImage("button1", preloaded[1][1].src) };

     menu1.onactivate = function() { swapImage("button2", preloaded[2][1].src) };
     menu1.ondeactivate = function() { swapImage("button2", preloaded[2][1].src) };

     menu1.onactivate = function() { swapImage("button3", preloaded[3][1].src) };
     menu1.ondeactivate = function() { swapImage("button3", preloaded[3][1].src) };

     menu1.onactivate = function() { swapImage("button4", preloaded[4][1].src) };
     menu1.ondeactivate = function() { swapImage("button4", preloaded[4][1].src) };

     menu1.onactivate = function() { swapImage("button5", preloaded[5][1].src) };
     menu1.ondeactivate = function() { swapImage("button5", preloaded[5][1].src) };
    
     menu1.onactivate = function() { swapImage("button6", preloaded[6][1].src) };
     menu1.ondeactivate = function() { swapImage("button6", preloaded[6][1].src) };
    
     menu1.onactivate = function() { swapImage("button7", preloaded[7][1].src) };
     menu1.ondeactivate = function() { swapImage("button7", preloaded[7][1].src) };
    
     menu1.onactivate = function() { swapImage("button8", preloaded[8][1].src) };
     menu1.ondeactivate = function() { swapImage("button8", preloaded[8][1].src) };
    
    }
   }

   // this is a crappy example preloader. Use whichever one you want.
   function loadImage(sFilename) {
    var img = new Image();
    img.src ="_images/nav/" + sFilename;
    return img;
   }

   // this is a crappy example image swapper. Use whichever you want.
   function swapImage(imgName, sFilename) {
   document.images[imgName].src = sFilename;
   }