Задание обработчиков кнопок в цикле

[this.create]

function initNav1() {
    var i = 0;
    while (i<menu.length) {
        var mc = mc_menu.attachMovie("nav1_item", "mc_nav1_item_"+i, int(i+100), {_x:i*100 ; _y:0});
        var bt = mc.attachMovie("button", "mc_bt_"+i, int(i+110));
        //описание кнопки
        bt.onRollOver = function() {
            mc.mc_text_on._alpha = 100;
            mc.mc_text._alpha = 0;
            trace(this);
            trace(this._parent);
        };
        bt.onRollOut = function() {
            mc.mc_text_on._alpha = 0;
            mc.mc_text._alpha = 100;
        };
        i++;
    }
}