Source of User Defined functions.

Hello,

I have a questions regarding the location of source code of user defined
functions in Postgres. I used the following query to get all function names
but I
do not see the source code of the user defined functions. In the 'prosrc'
column, data is available for trigger functions only. Is there any other
table/column where function source code can be found?

SELECT p.proname, p.pronargs, t.typname,p.proowner, p.prosrc
FROM pg_proc p, pg_language l, pg_type t
WHERE p.prolang = l.oid
and p.prorettype = t.oid
and l.lanname in ('sql', 'plpgsql' )
and proowner = 964227
ORDER BY proname;

Thanks much
Saii