How to catch a login in SAP?

Hi Experts,

I would like to inform an administrative person when someone try to login to SAP.

I've found a FM SUSR_LOGON_USER_EXIT and when the login is success i can see who is trying to login because i put a break point in my user exit

SUSR0001.

But when the login is failed it doesn't pass trought my breakpoint. So, i find the message class in trx SE91 message e152(00).

Now, i look all the programs where it appears this message and i created an enhancement-point to put a BREAK-POINT, how ever nothing's happened.

I've no more ideas how to catch when the login is failed, it's urgent!!!

PD: When i'm debbuging SUSR_LOGON_USER_EXIT the main program is SAPMSYST but it's protected, so i can't do anything else.

Regards.