Loading big swf


I am having a pretty huge swf file (animation) - about 5MB
I thought that if people should preload the whole file, it would take some time (especially for people with slow connections)

So I have heard about a method that allows to load (let’s say) 1/3 of the whole flash and begind playing it, so while ppl are enjoying the first (out of 3) part, it should load the second part, and when people are watching the second part (still ot of 3), it should load the last part.

Any suggestions on how to do it?

Thanks for all help