mo = [];
mo.images = [];
mo.base = 'template/gfx/nav/';

mo.enter = function(el) {
   for (var i = 0; i < el.childNodes.length; i++) {
      var node = el.childNodes.item(i);
      if (node.nodeType == 1 && node.tagName.toLowerCase() == 'img' ) {
         if (this.images[node.id]) {
            node.src = this.images[node.id][1].src;
         } else if (this.images[node.name]) {
            node.src = this.images[node.name][1].src;
         }
      }
   }
}

mo.exit = function(el) {
   for (var i = 0; i < el.childNodes.length; i++) {
      var node = el.childNodes.item(i);
      if (node.nodeType == 1 && node.tagName.toLowerCase() == 'img' ) {
         if (this.images[node.id]) {
            node.src = this.images[node.id][0].src;
         } else if (this.images[node.name]) {
            node.src = this.images[node.name][0].src;
         }
      }
   }
}

mo.preload = function(name, normal, hover) {
   mo.images[name] = [];
   mo.images[name][0] = new Image()
   mo.images[name][0].src = this.base + normal;
   mo.images[name][1] = new Image()
   mo.images[name][1].src = this.base + hover;
}