External SWF reload issue

i have 5 external SWF files which loads on the 0th level of flash file (one at a time). one common navigation is located at the 1st level where I can select to have one of the 5 different SWFs loaded on 0th level.

the problem is- within the navigation SWF (at 1st level) i have a “Refresh” button which should refresh the SWF file loaded at 0th level when clicked. BUT how do i know which SWF is loaded on 0th level in order to refresh it…

any suggestions?