Sold my Macbook - did I delete files correctly?

I just want to make sure I did what I was supposed to when clearing out old files. The first thing I did was reset safari (clean cache & threw away old applications)

Next I did the following:

1) I put the installer disc in.

2) Disc Utility

3) Erase Files

4) 7-Pass Erase (took an hour or so)

Last: (took about an hour)

I then did a fresh install of OSX. When it was done, I got the screen to do the initial set-up of the Macbook. (Language, Connection, Mac Account, etc...)

It may have been overkill - but I didnt want my old files to be accessible. -- Thanks