How to save and email a swf?

I just got Flash 8 today, specifically so that I could use the BitmapData class.

I have written a Whiteboard application. When the users have finished scribbling, they can print the image, no worries.

But, I need to let them SAVE the image (as a bmp or jpeg etc) and then email it.

So…I’m thinking I have to do something like this:

var drawing:BitmapData = new BitmapData(Stage.width, Stage.height, true, 0);

…to save the image.

Then somehow pass this BitmapData out to a PHP function, which will then build a bmp.

This is where I am struggling, I have found tutorials for grabbing a frame of a video, but this is just a static mc.

Can anyone explain to a simple soul like me how I pass the correct data from a BitmapData object out to a PHP file ?

Thank you so much.

My brain hurts. (again)