"login" keychain password with reformatted hard drive?

I just reformatted my hard drive in order to sell it, and in order to reinstall OSX 10.7 I need to be connected to the internet ... after entering our WAP2 password it asked, "airportd wants to use the 'login' keychain. Please enter the keychain password."

None of my current or past passwords for the admin account have worked, and I'm at a loss as to what it could possibly be. Is there a default admin password I can use?