attachMovie with fade?

1

I’m trying accomplish a fade-in for my attached
movies, using this script:

nr = 1;
tot = 8;
MovieClip.prototype.attach = function(base) {
    base["content"+nr].attachMovie("mc"+nr, "clip"+nr, nr);
    if (nr == tot) {
        clearInterval(id);
    }
    nr++;
};
id = setInterval(attach, 1000, this);
MovieClip.prototype.fadein = function(base) {
    for (i=1; i<5; i++) {
        base["content"+i]._alpha = 0;
        base["content"+i].onEnterFrame = function() {
            this._alpha += 3;
            if (this._alpha>=100) {
                this._alpha = 100;
                delete this.onEnterFrame;
            }
            clearInterval(mc);
        };
    }
};
mc = setInterval(fadein, 1000, this);

But it doesn’t work. Can somebody help me out with this?

thanks
example here