help,why I cannot use graphical interface of remote workstation?

Dear all,

Fist I  apologize for my bad english.
I use the Fedora Core3.  I want to use the graphical interface of
remote workstation. I do as following:

1) In my computer: xhost +
2) I use ssh command to connect the remote workstation
   I use the command like: setenv DISPLAY xxx.xxx.xx.xx(my IP):0.0

   But I still cannot use the graphical interface. The warning information
   indicates that it unable to open display.  What is the wrong?

what can I do for this problem?