Changing SWFs?

this might be a easy fix, but im just starting.

i have two swf that i made… and i have them both linked up to each other called link 1 and link 2. when i click on link 2 it opens up the new swf on top of the old one (link 1). how do i close the old swf (link1). (because if i click back to link 1 it opens a new link 1 swf. but also has the original link 1 underneath it and you can see it for a split second. )

is there anyone that can help… i used the full site tutorial
thanks