[TYPO3-dev] Backend module development help

[Fred]

Hello,

I'm writing a backend module, and I'd like to use an personalized
navFrame to browse differents elements.
But I don't know exactly how to get this nav frame (like Page or DAM
browser).

I've already put a :
$MCONF["navFrameScript"]='tx_test_navframe.php';
in the conf.php, and written the tx_test_navframe.php file.
The frame is there, but with an Apache error :
The requested URL /typo3/" top.TS.PATH_typo3
"../typo3conf/ext/myextension/mod1/tx_test_navframe.php was not found on
this server.

Why "top.TS.PATH_typo3" is not changed to a real path ?

I can't understand this.
Does anybody can help me ?

Thanks,
Fred.