Modify The Document
From the menu select Modify, Document. In the pop-up window you can set the size of the movie, the background color, and the number of frames per second. The default speed is 24 frames per second. Select a new color and make the size the same as the one shown here, 400x400.
INDEX, Demo of Flash Environment, Flash uses Strokes and Fills, Working with layers, Modify Document
Next lesson: Project: An Ad for a Garage Sale