postgres bash prompt error while user creation

hello group
  i want to create a shell script  in that i want to create postgresql
user and database.both this task are created properly and executed
properly but after user and DB creation i am there on ( -bash-3.00$  )
and i wanna come back to [root@localhost:localdomain ~]#  and my
script is
#!/bin/bash
su -l postgres;
psql -U postgres -c "CREATE USER admin27 WITH PASSWORD 'admin27'
CREATEDB;" template1
psql -U admin27 -c "CREATE DATABASE emcc27;" template1 \q exit;
plzz help me to back to root from postgres bash prompt