Javascript tab menu loading after Google Ads

I utilized a tab menu written in HTML and CSS and running with javascript. The tab menu can be seen working here as DD Tab Menu. Everything works great except one issue: when I add Google Ads, it will not load until Google ads is loaded. The Google Ads is set 'async' so it is supposed to load last.

Usually one doesn't notice, however some times when there is a problem with the Google ads network, the tab menu will not load. I could not figure out why. The javascript for the tab menu is:

var tabmenu={
    disabletablinks: true, 
    snap2original: [false, 300], 

    currentpageurl: window.location.href.replace("http://"+window.location.hostname, "").replace(/^\//, ""), 

definemenu:function(tabid, dselected){
    this[tabid+"-menuitems"]=null
    this[tabid+"-dselected"]=-1
    this.addEvent(window, function(){tabmenu.init(tabid, dselected)}, "load")
},

showsubmenu:function(tabid, targetitem){
    var menuitems=this[tabid+"-menuitems"]
    this.clearrevert2default(tabid)
 for (i=0; i<menuitems.length; i++){
        menuitems[i].className=""
        if (typeof menuitems[i].hasSubContent!="undefined")
            document.getElementById(menuitems[i].getAttribute("rel")).style.display="none"
    }
    targetitem.className="current"
    if (typeof targetitem.hasSubContent!="undefined")
        document.getElementById(targetitem.getAttribute("rel")).style.display="block"
},

isSelected:function(menuurl){
    var menuurl=menuurl.replace("http://"+menuurl.hostname, "").replace(/^\//, "")
    return (tabmenu.currentpageurl==menuurl)
},

isContained:function(m, e){
    var e=window.event || e
    var c=e.relatedTarget || ((e.type=="mouseover")? e.fromElement : e.toElement)
    while (c && c!=m)try {c=c.parentNode} catch(e){c=m}
    if (c==m)
        return true
    else
        return false
},

revert2default:function(outobj, tabid, e){
    if (!tabmenu.isContained(outobj, tabid, e)){
        window["hidetimer_"+tabid]=setTimeout(function(){
            tabmenu.showsubmenu(tabid, tabmenu[tabid+"-dselected"])
        }, tabmenu.snap2original[1])
    }
},

clearrevert2default:function(tabid){
 if (typeof window["hidetimer_"+tabid]!="undefined")
        clearTimeout(window["hidetimer_"+tabid])
},

addEvent:function(target, functionref, tasktype){ //assign a function to execute to an event handler (ie: onunload)
    var tasktype=(window.addEventListener)? tasktype : "on"+tasktype
    if (target.addEventListener)
        target.addEventListener(tasktype, functionref, false)
    else if (target.attachEvent)
        target.attachEvent(tasktype, functionref)
},

init:function(tabid, dselected){
    var menuitems=document.getElementById(tabid).getElementsByTagName("a")
    this[tabid+"-menuitems"]=menuitems
    for (var x=0; x<menuitems.length; x++){
        if (menuitems[x].getAttribute("rel")){
            this[tabid+"-menuitems"][x].hasSubContent=true
            if (tabmenu.disabletablinks)
                menuitems[x].onclick=function(){return false}
            if (tabmenu.snap2original[0]==true){
                var submenu=document.getElementById(menuitems[x].getAttribute("rel"))
                menuitems[x].onmouseout=function(e){tabmenu.revert2default(submenu, tabid, e)}
                submenu.onmouseover=function(){tabmenu.clearrevert2default(tabid)}
                submenu.onmouseout=function(e){tabmenu.revert2default(this, tabid, e)}
            }
        }
        else //for items without a submenu, add onMouseout effect
            menuitems[x].onmouseout=function(e){this.className=""; if (tabmenu.snap2original[0]==true) tabmenu.revert2default(this, tabid, e)}
        menuitems[x].onmouseover=function(){tabmenu.showsubmenu(tabid, this)}
        if (dselected=="auto" && typeof setalready=="undefined" && this.isSelected(menuitems[x].href)){
            tabmenu.showsubmenu(tabid, menuitems[x])
            this[tabid+"-dselected"]=menuitems[x]
            var setalready=true
        }
        else if (parseInt(dselected)==x){
            tabmenu.showsubmenu(tabid, menuitems[x])
            this[tabid+"-dselected"]=menuitems[x]
        }
    }
}
}

Select allOpen in new window

Any assistance is appreciated. Thanks in advance.