check rights for executing stored procedure not for logged user

From: Thomas Münzer (t.muenzer@mkl-gmbh.de)
Date: 05/29/02 

From: Thomas Münzer <t.muenzer@mkl-gmbh.de>
Date: Wed, 29 May 2002 04:57:35 -0700

I need to check weather user X with password Y has the
right to execute a special stored procedure.
The problem is that I need to check this while user A is
logged in.
Is there a way to do this ?