Snow 3.0 tutorial help

I am trying to use the snow 3.0 tutorial. I want to mask the effect so it looks like it is in a snow globe but what ever i do, it won’t let me mask it. I tried a timeline mask, and an actionscript mask and neither worked. Any help would be appreciated.

Here is the code.

init = function () {
width = 300;
// pixels
height = 200;
// pixels
max_snowsize = 10;
// pixels
snowflakes = 50;
// quantity
for (i=0; i<snowflakes; i++) {
t = attachMovie(“snow”, “snow”+i, i);
t._alpha = 20+Math.random()60;
t._x = -(width/2)+Math.random()
(1.5width);
t._y = -(height/2)+Math.random()
(1.5height);
t._xscale = t._yscale=50+Math.random()
(max_snowsize10);
t.k = 1+Math.random()2;
t.wind = -1.5+Math.random()
(1.4
3);
t.onEnterFrame = mover;
}
};
mover = function() {
this._y += this.k;
this._x += this.wind;
if (this._y>height+10) {
this._y = -20;
}
if (this._x>width+20) {
this._x = -(width/2)+Math.random()(1.5width);
this._y = -20;
} else if (this._x<-20) {
this._x = -(width/2)+Math.random()(1.5width);
this._y = -20;
}
}
init();