login as oracle user and at the comand prompt say
startx

and then do thisUse a text editor to edit the .bash_profile file in the oracle account home directory.
$ emacs ~oracle/.bash_profile

You may get this error:
Xlib: connection to ":0.0" refused by server
Xlib: Client is not authorized to connect to Server
emacs: Cannot connect to X server :0.
Check the DISPLAY environment variable or use `-d'.
Also use the `xhost' program to verify that it is set to permit
connections from your machine.

If so, do the following.
Open a new terminal window.
$ xhost +localhost
Now, back in the oracle terminal
$ export DISPLAY=localhost:0
$ emacs ~oracle/.bash_profile


Start a new terminal
$ xhost +localhost
$ su - oracle
Enter oracle password
$ export DISPLAY=localhost:0.0



Try this procedure
hth
hrishy