Loading external SWF. How to setting its relative path?

Hi guys, Im really getting a headache with this.
I am trying to create a flash PDF viewer, among other things, which will load various other "book" swf files. The viewer will be in the root directory, but the "book" swf files it will load are a few directories above them.

/main_viewer.swf
/content/book1/book1.swf
/content/book2/book2.swf

It seems that when I load one of these swf into my viewer, the loaded swf is looking for the files from the root directory, and not relative to the swf I loaded. Is there a way to set this?

Here is my flash project focused in that problem:
http://www.mediafire.com/?w32rqqq55l51w47

Thanks