catch password on Postgres server

Greetings,

Postgres 7.4 running on RedHat 9.

We are trying to migrate a MS SQL server based comertial application
software to a Postgres database.  We know what password that application
uses to connect to the MS SQL database.  The password has five letters.
We've set up the same user on the Postgres server.  However, when the
application software connects to the Postgres database through the
PostgreSQL ODBC driver, the Postgres server always shows 'password
authentication for user ...' in the log file.  I even tried all the
permutations of the letters in various cases that make up the password.
None works.  I'm completely lost.  Is there anyway on the server side to
see what was  submitted in the password field by the application from the
client side?

Any help would be greatly appreciated.

Bing