Modifying falling snow

I’m designing a site for a bar, and in the header I have a beer mug. I am trying to reverse the code so that the snow goes up (creating a carbonation effect). I deleted the horizontal code, and negated the vertical code, but now the effect doesn’t continue. It’s just one group of bubbles and that’s it. Can anyone tell me what I’m doing wrong? www.peaseblog.com/L29
Here is my action script:
onClipEvent (load) {
//variables
width = 751;
height = 200;
//random x,y, and alpha
this._xscale = this._yscale=50+Math.random()100;
this._alpha = 20+Math.random()50;
//random x and y for flakes
this._x = -width+Math.random()
(3
width);
this._y = -10+Math.random()*height;
//speed and trigonometric value
i = 1+Math.random()2;
k = -Math.PI+Math.random()Math.PI;
rad = 0;
}
onClipEvent (enterFrame) {
// vertical movement
this._y -= i;
// remove clips when they misbehave (overstep boundaries)
if (this._x>(width+50)) {
this._x = -45;
this._y = Math.random()height2;
}
if (this._x<-50) {
this._x = width+45;
this._y = Math.random()height2;
}
if (this._y>=height) {
this._y = -50;
this._x = -width+Math.random()
(3
width);
}
}