Boot problem after reboot during upgrade from frebsd6.1 to freebsd7.0

[Yavuz Maslak]

I followed http://www.freebsd.org/releases/7.0R/announce.html  to upgrade
freebsd6.1 to 7.0.

I forgot compile kernel for freebsd7.0. and I rebooted the machine.
The server didn't give any error message during the upgrade.
The server tried to boot at freebsd6.1. and it could not boot the system. it
came " Enter full path of shell" on the screen.
How can I do correct that ?