Randomise frame event

[tariqm]

You can create a counting integer variable that adds every time it enters the snowflake function and a goal variable to tell the function at which frame number to initiate the code in the function, like this:

stage.addEventListener(Event.ENTER_FRAME, snowflake);
//init variables
var count:int=0;
var goal:int=int(Math.random()*50+50);//this will give you a number from 50-100

function snowflake(event:Event):void{
   if(count>=goal){
       count=0;
       goal=int(Math.random()*50+50);
       //add your code that was initially in your function here
   }
}

I believe this would work, there may be an error in the code, have not checked it.