Bigger Picture Films

You absolutely rock. What a simple solution! And to think I *gasp* spent hours of stressful hunting. I should've asked sooner. Thanks again!

How do you animate values like the rate of emission to start/stop a particle material from generating particles? I've figured out the way to animate things like opacity, size, and gravitational effect, but stopping and starting the effect using rate of emission eludes me. An example of where it's done is the Explosion Project in the Animation: master libraries. I'm sure most of you know what I'm talking about. Whoever can answer this for me absolutely rocks. Even if you don't answer, you probably rock anyway.