Problem Starting Postgresql after upgrade from SuSE8.1 to SuSE 8.2

I upgrade to SuSE 8.2 and it upgraded Postgresql from 7.2 to 7.3.2. I
use a script file to start Postgresql, this is the contents.

#!/bin/sh
/usr/bin/postmaster -i -D /usr/share/pgsql/data


And now this is what I get:

john@linux:~> ./sql
FATAL:  The data directory was initialized by PostgreSQL version 7.2,
which is not compatible with this version 7.3.2.
john@linux:~>

My question is, "What to do now to get access to my postgresql data
files? I can correct this?"

Thanks for your help

John