Oracle Database Discussions

Hi

i want to use dbca utility from my client machine(rehel 4)
i logon through ssh and set variable

export DISPLAY=:0.0
xhost +

than i run dbca it is giving this error what can be the cause.

ERROR: Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified

Exception in thread "main" java.lang.InternalError: Can't connect to X11 window server using ':0.0' as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
at sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:134)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:141)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62)
at java.awt.Font.initializeFont(Font.java:308)
at java.awt.Font.<init>(Font.java:344)
at oracle.ewt.lwAWT.LWComponent.<clinit>(Unknown Source)
at oracle.sysman.assistants.util.wizard.WizardObject.<init>(WizardObject.java:63)
at oracle.sysman.assistants.dbca.ui.DBCAWizard.<init>(DBCAWizard.java:424)
at oracle.sysman.assistants.dbca.ui.UIHost.<init>(UIHost.java:209)
at oracle.sysman.assistants.dbca.ui.InteractiveHost.<init>(InteractiveHost.java:54)
at oracle.sysman.assistants.dbca.Dbca.getHost(Dbca.java:155)
at oracle.sysman.assistants.dbca.Dbca.execute(Dbca.java:93)
at oracle.sysman.assistants.dbca.Dbca.main(Dbca.java:175)

please tell me
Thanks