reverting back both working copy and commits

Hi,

I made some commits that later on I wanted to cancel. I did:

% git-branch master-2006-get-rid-of-commits

% git-reset --hard [sha1id]

where sha1id is the id of commit I want to revert back to. After this,
git-log points at the right commit (the one with [sha1id]) as the last
commit made. However, the working copy is left in the original state,
i.e with the unwanted changes.. How do I also revert the working
sources into an earlier state.

Because git-commit says "nothing to change" at this stage, git
checkout -f does not cure my problem. How do I also revert working
copy to earlier commit?

Thanks,
Bahadir