Keyboard cannot input char under gnome login

[wason wei]

Dear all,

My keyboard work well under command mode of Freebsd.  Yesterday, I 
install gnome by the sysinstall command, and then add a new line: 
gdm_enble="YES"  to /etc/rc.conf .  After I reboot the system, I can 
enter the gnome window, but I found that I cannot type any char in the 
username input box. and hence I cannot login to the gnome due to the 
bad username and password.  Then worse thing is that I cannot return to 
the command mode, either.  and I cannot use my computer now.

What should I do?  If you have any idea about this, Please contact me 
without hesitation. I am waiting for your reply.

wason wei,
2005-11-20