4
And people are willing here to help.
But I think, people want to "teach how to fish" instead of "giving you a fish".
So they prefer you to try something and come and say: "I've tried this and this, and it doesn't work. What am I doing wrong?"
In case, I don't have the answer. You can define size for Flash movie. You can Google an that on how to do it. Then you have to find out how to get the size of the actual screen (it will vary between users), and see if you can set the width of the Flash as "relative width" based on the actual screen width.
Easier way would be to set the width of your Theme to something like 800 pixels, and then set the Flash that width. This way regardless of the size of the user's monitor, your Website will be always looking the same.