How to revert from Maverick to previous OS

Ok I read the article about how to revert from mavericks to previous OS. But it's a bit late for that method because I already had erased the hard drive using the disk utility during boot up. Now when I click on reinstall OS, mavericks shows up. And I don't want it, I want to instal the original OS I had when I bought my MacBook Pro. How can I do that? Without having to endure mavericks again? It made my computer run twice as slow. No Wonder it was free...