I'm creating a flash widget and i want the user to be able to control the width and height of the widget by just changing the width and height parameters in the embed html code.

I'm having some issues getting it to work properly.

Is the stage size determined by the width and height tags or by the width and the height of the swf when it is published?

Does anyone have any experience with something like this?

I think you normally create the swf larger than needed and then get the html to show it (it gets masked), then get flash to call javascript with a parameter and change the html on the fly. I have posted something about it here, I used it on a site that had tweens between 'pages' of different lengths.