Customizable fog / smoke / cloud animation to put in the foreground of any animation / movieclip you like. The fog is easily created by importing the SWC library and adding it to your file with one line of code. You can add as many fogs as you like, at different positions and speed.
The preview shows two fogs running at 20 and 50 seconds per loop, and positioned at 0 and -70 y, respectively.
The fog supports projects of up to 1280 by 1024 pixels in size.
Customizable parameters: y position, speed
Code to add fog: var fog1:Fog = new Fog(10,100); (and then add the returned Movieclip, which Fog can be treated as, to whatever you like)
UPDATE : Now works with both Flash CS4 and CS3 .