.profile

Hi,

I have entry in .profile like this :

alias GH='. /opt/dba/oraadmin/tools/gh.sh'

and gh.sh script has some thing like this :

#!/bin/ksh
echo "Setting the GRID_HOME env variables"
ORACLE_SID=GRID_HOME;export ORACLE_SID
ORACLE_HOME=$GRID_HOME;export ORACLE_HOME
PS1="`whoami`@`hostname`:`pwd` ^[[1m${ENVIRON}^[[0m [GRID_HOME]$ "

after executing GH in shell , the command prompt stays as is , I mean the value not changing after that ( like cd .. , cd to/another/dir ) ..

what I am missing here ?

Are you exectuing a new shell somewhere?
note: after executing GH in shell
This
try:

set | grep PS1
. . /opt/dba/oraadmin/tools/gh.sh
set |  grep PS1

Your PS1 declaration will work for bash IF you source the shell GH is called in. Environment variables do not pass from a child back to the parent process.