Open external text in dynamic textbox in another frame

Hey,

hope you can help me out with this one:

I have a site with three frames: leftFrame, upperFrame and mainFrame.

in the ‘leftFrame’ is my flash menu. In the mainFrame is a dynamic textbox, where I want to load text in (if pressed on one of the flash buttons on the leftFrame) from a external textfile.

I used this tutorial http://www.kirupa.com/developer/mx/multiple_dynamictext.htm
but it doesn’t work with frames!

Thanks in advance!
Tipsko <:}