Stuck on restarting a movie when loop completed

programming flash
1

I have a simple FLA which loops through some keyframes and randomly places movie clips on the stage.

Frame 1:
Contains nothing

Frame 2:

_root.tile.duplicateMovieClip("tile"+i,i+1)
_root["tile"+i]._x=Math.random()*800;
_root["tile"+i]._y=Math.random()*600;
this = Math.random()*100;
_root["tile"+i]._xscale=this;
_root["tile"+i]._yscale=this;
_root["tile"+i]._alpha=Math.random()*100+10;

Frame 3:

if(i<100){
    ++i
    gotoAndPlay(2)
}else{
    gotoAndStop(4)
}

Frame 4:

i=0;
stop();

On Frame 4, I add a button which I’d like to use to restart the whole thing.

The button has this AS on it:

on (release) {
    i=0;
    var ref = null;
    for(i in this)
    {
        if(typeof (ref = this*)  == "movieclip")
            ref.removeMovieClip();
    }    
    gotoAndPlay(1);    
}

But when I click the button, it doesn’t restart at all.

The SWF example is here:
http://jimpix.co.uk/junk/christmas-rainbows.swf

If it helps, the FLA is here:
http://jimpix.co.uk/junk/christmas-rainbows.fla

Any advice about what I’m doing wrong would be gratefully received.

Thanks!