Actionscripted Fire

I am currently trying to make a game, but there are in some parts where i need to add a fire (for a campfire and a candle).
I am very bad when it comes to animating things, so animating my own campfire isn’t an option.
I’ve seen an actionscripted fire been used before in other flash animations and games, so i was hoping that any of you would know how to make an actionscripted fire.