What I want to do is have a small 10 second website advertisment play before the game becomes active. Is their a way to have one flash file play and when it is finished it starts the other one?
Sure it's possible. How you do it will depend on what tools and skills you have.
First, it could be done in Flash, inside the .fla.
Second option is to configure swfobject to play one after another. Check out this link rescently posted here in the Forum:
Lots of great ways to expand Flash functionality without using Flash.
I am not able to edit the swf files. i couldnt find anything on that link you sent me. is their a way of placing the two swf urls in some html code and after a certain amount of time one disappears and the other starts up?