Can't Log Into Admin AREA!

all of a sudden i am getting an error.
Errors that occured while trying to enter admin area


You entered the wrong username
You entered the wrong password



site is

http://www.missionknive.com/admin

im doing a site for a friend.

please help

Please don't post the same question more than once. You get a reputation and it just discourages us from answering in case somebody else has already answered you somewhere else.