onClipEvent (load) {
    lastx = 0;
    lasty = 0;
}
onClipEvent (enterFrame) {
    if (Key.isDown(Key.RIGHT)) {
        this._x++;
    } else {
        if (Key.isDown(Key.LEFT)) {
            this._x--;
        }
    }
    if (Key.isDown(Key.UP)) {
        this._y--;
    } else {
        if (Key.isDown(Key.DOWN)) {
            this._y++;
        }
    }
    if (_root.ground.hitTest(this._x, this._y, true)) {
        //trace("touched!");
        this._x = lastx;
        this._y = lasty;
    }
    lastx = this._x;
    lasty = this._y;
}