Install

hi,
   I have Redhat 6.2 and just installed Postgres

   Well i just rpmed packaages
        postgresql-6.5...
        postgresql-server...

   Well now if i do
   su postgres

   bash$ createdb sameer
   Connection to database 'template1' failed.
   connectDB() -- connect() failed: Connection refused
   Is the postmaster running at 'localhost' and
   accepting connections on Unix socket '5432'?

   createdb: database creation failed on sameer.

   Please help

   Sameer