Not able to login in the graphical interface

dear freinds
when i log into the graphical interface in the redhat Redhat enterprises linux v3 ,there is an error message i receive it says
(your session only lasted less then 10 seconds .If you have not logged out yourself ,this could mean that there is some installation problem or that you may be out of disk space ,try logging in with one of the failsafe sessions to see if you can fix this problem )
can some one try to help me by reading the above error message
thanx in very much in advance

I haven't seen that message, but this is what I would try. Press CTRL-ALT-F2 to get to a console text-mode login prompt. (CTRL-ALT-F7 or maybe -F8 takes you back to the graphical login.)

Try to login as root.
If you succeed, the df command will show you how full each disk is.
Look toward the end of /var/log/messages and /var/log/syslog for anything interesting.
Verify that your username has a directory under /home owned by that user.