Mimic Browser's Back Button

I have a Flash file stored inside of the LMS Blackboard - when users log into Blackboard they can open the file without a problem. Inside that flash file I have a link to a 2nd (and separate) Flash file that is outside of Blackboard. I can easily link from Flash file 1 to Flash file 2 using a URL link and can click on the browser’s back button to get back to the 1st file. However, I think it would be more intuitive if I could add a button to the second flash files that says “Click here to go back to the original case” rather than including instructions for using the browsers back button.

The catch - I can not directly link to the URL of the 1st Flash file stored in Blackboard because it requires session variables and encrypted login credentials.

Is there a way to create a button in the 2nd flash file that mimics the behavior of the browser’s back button? If not, I can just instruct users to use the Back button - but I’d like to avoid it if possible.

Thanks for any help you can give me!!

PS - Because of the complications of Blackboard, Flash, and extraneous files (image files that are loaded dynamically) - I am hoping to avoid embedding the second file inside of the first. Blackboard has not reacted well to this combination!