[Typo3] extending newloginbox

[Michael Courcy]

Hi list

I try to extend the newloginbox extentension, only the class 
tx_newloginbox_pi1 wich is in the file  pi1/class.tx_newloginbox_pi1.php 
because I want to check few things about the feuser when is logging.

So I follow carefully the modern template building part 2 where 
extending an existing class is explained. But Kasper explain how to 
extend a class wich is not in the typo3conf directory....

So I decide to make some attempt on my own to figure out the mecanism 
involved
1) I create the directory my_extension
2) I made my_extension/ext_emconf.php
3) I made my_extension/class.my_newloginbox.php where I extend the class 
tx_newloginbox_pi1
4) I made my_extension/ext_localconf.php where I put this code on wich 
I'm very unsure

       
$TYPO3_CONF_VARS["FE"]["XCLASS"]["typo3conf/ext/newloginbox/pi1/class.tx_newloginbox_pi1.php"] 
=
        t3lib_extMgm::extPath('my_extension').'class.my_newloginbox.php';

5)I installed the extension


But everything look like the tx_newloginbox_pi1 has not been extended 
......... snif ..........

I know that that my problem is not easy to understand, and there could 
be probably million of reasons that make this process fail, it's why 
i'll be very pleased if someone knew an expample of frontend extension 
that extends an other frontend extension already leaving in the 
typo3conf directory.

So I could look how they manage their buisness and understand what's 
wrong with mine.

I you read me until there thank you very much.

Michael.