How to disable functions?

say i came up with a function like this:

[AS]
function addSnowflake():Void {
var depth:Number = this.getNextHighestDepth();
var snowflakeClip:MovieClip = this.attachMovie(“circle”, “snowflakeClip”+depth, depth);
var scaleFactor:Number = Math.random()*80+20;
}
[/AS]

how do i disable it with a press of a button?

umm, if you guys are kind enough, how do you think i can control the number of snowflakes…

thanks and please help!