function prepareMainMenu() {
    var menu = document.getElementById('mainlevel');
    var active = document.getElementById('active-menu');
    if( menu && active ){
        //var items = menu.getElementsByTagName('li');
        var items = menu.childNodes;
        for( i=0 ; i<items.length ; i++ ){
            if( items[i].childNodes[1] ){
                if( active.parentNode.parentNode==items[i] )
                    items[i].childNodes[1].style.display = 'block';
                else
                    items[i].childNodes[1].style.display = 'none';
                items[i].childNodes[0].onclick = function () {if(this.parentNode.childNodes[1].style.display=='block') this.parentNode.childNodes[1].style.display='none'; else this.parentNode.childNodes[1].style.display='block'; return false;}
            }
        }
    }
}