did you backup your
commandmenu.txt???.
if you did then just copy your backup file back.
if you didn't back it up here is mine backup one.
just download it and copy it into your cstrike directory and it will give you back your only commands.
Always backup files that you change.
Edit
this is the command menu for CS 1.5.
if you have 1.6 then you will have to reinstall

, or ask someone for a commandmenu.txt for 1.6.