assign own onclick function

tree = new Mif.Tree({
    initialize: function(){
        function myFun(event){
            var node=this.mouse.node;
            /*var target=this.mouse.target;
            if(!['icon','name'].contains(target)) return;*/
            if(!node) return;
            alert('node ' + node.name + ' clicked');
        }
        this.wrapper.addEvent('click', myFun.bind(this));
    },
...