Importing 3D studio max video???

You have to render the movie from 3DSMax, first. Render it as an AVI, and DO NOT COMPRESS THE MOVIE. You can let Flash do that when you import it. 3DSMax has no particular format for video--it simply renders the display to either a video file (AVI, MPEG, etc) and applies a compression codec (if you want to compress it...) to shrink the file size, or renders to image files (BMP, JPG, etc) using whatever compression method used for the file type. For this, obviously, you want a movie--use AVI as your format, using "Full Frames (Uncompressed)" as your compression option.

Then, after the movie is rendered (it will be huge uncompressed!), you can import it into Flash and compress it using the Sorenson Sparq codec (which shrinks it down signifigantly--keeping a decent quality level).

Play around with compression to get the file size and quality level you're going for. You'll have to re-import the movie every time you want to recompress it.

Another option for 3DSMax scenes is you can render them in vectors with Swift 3D (remember that vectors aren't as detailed as a rasterized/bitmap image!) This works well if you're not going for detail, and works best with basic shapes--the RAVIX rendering engine for Swift3D is much slower than the 3DSMax rendering engines, so the more polygons you have, the longer it will take to render a simple vector animation...complex models can really take several nights to render just a few seconds of animation!

Hope this helps. :)