var top_nav = {
    isHovering: false,
    hoverImage: "top_round_hover.gif",
    nonHoverImage: "top_round.gif",
    targetEl: "level-two-nav-top",
    swap: function() {
        if(this.isHovering){
            this.isHovering=false;
            document.getElementById(top_nav.targetEl).style.background   = "url(/menujs/"+top_nav.nonHoverImage+") no-repeat bottom left";
        }
        else
        {
            this.isHovering=true;
            document.getElementById(top_nav.targetEl).style.background  = "url(/menujs/"+top_nav.hoverImage+") no-repeat bottom left";  
        }
    }
 };
 
 var btm_nav = {
    isHovering: false,
    hoverImage: "btm_round_hover.gif",
    nonHoverImage: "btm_round.gif",
    targetEl: "level-two-nav-btm",
    swap: function() {
        if(this.isHovering){
            this.isHovering=false;
            document.getElementById(btm_nav.targetEl).style.background = "url(/menujs/"+btm_nav.nonHoverImage+") no-repeat top left";
        }
        else
        {
            this.isHovering=true;
            document.getElementById(btm_nav.targetEl).style.background = "url(/menujs/"+btm_nav.hoverImage+") no-repeat top left";            
            
        }
    }
 };
 
 function attachListener( el, type, func ){if(window.addEventListener){el.addEventListener(type,func,false);return true;}else if (window.attachEvent){el.attachEvent('on'+type,func);return true;}return false;}
 function getLi( ulEl, first ){if(first){if(window.addEventListener){ return ulEl.firstChild.nextSibling; }else { return ulEl.firstChild; };}else{if(window.addEventListener){ return ulEl.lastChild.previousSibling; }else { return ulEl.lastChild; };}}

 var preloader = new Image();
 preloader.src = top_nav.hoverImage;
 preloader.src = top_nav.nonHoverImage;
 preloader.src = btm_nav.hoverImage;
 preloader.src = btm_nav.nonHoverImage;
 
 var ul_el = document.getElementById("level-two-nav").getElementsByTagName("ul")[0];
 var firstLi = getLi( ul_el, true);
 var lastLi = getLi( ul_el, false);
 attachListener(firstLi, 'mouseover', top_nav.swap ); 
 attachListener(firstLi, 'mouseout', top_nav.swap );
 attachListener(lastLi, 'mouseover', btm_nav.swap );
 attachListener(lastLi, 'mouseout', btm_nav.swap );