var menuRoles = {
        'ul.menu li' : function( elem ) {
           roundCorners( elem, "top transparent");
           if( elem.className != "selected" ) {
               elem.onmouseover = function() {elem.className = "selected";}
               elem.onmouseout = function() {elem.className = "";}
           }
        }
};
Behaviour.register( menuRoles );