Installtion error

Dear sir,
   Sir last one week i am try to install PostgreSQL in
Mac os x 10.2 .I dowm loaded PostgreSQL 7.3 from net
and i installed it in 'ampleuser', my login (in
dir:Library/PostgreSQL).

  After that i set the paths in follwing manner.And it
successfully starting the postmaster also.But when i
try to create the database its giving the error.
       Sir what is the error and plez give me solution
for it.

--------------------------
Mahesh-Ss-Computer:/Library/PostgreSQL] root# chown
ampleuser /Library/PostgreSQL/data

Mahesh-Ss-Computer:/Library/PostgreSQL] root# su -l
ampleuser

Mahesh-Ss-Computer:~] ampleuser%

[Mahesh-Ss-Computer:~] ampleuser% setenv PATH
${PATH}:/Library/PostgreSQL/bin

[Mahesh-Ss-Computer:~] ampleuser% setenv PGDATA
/users/ampleuser/data

[Mahesh-Ss-Computer:~] ampleuser%
/Library/PostgresqL/bin/pg_ctl -D
/users/ampleuser/data -l logfile start

postmaster successfully started

[Mahesh-Ss-Computer:~] ampleuser% createdb test
psql: could not connect to server: No such file or
directory
        Is the server running locally and accepting
        connections on Unix domain socket
"/tmp/.s.PGSQL.5432"?
createdb: database creation failed

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