Domain Name Transfer Contract - Anywhere to get a sample one?

[Azam.biz]

In the process of selling a domain name privately and was wondering if there were any sample contracts anywhere?

Also, has anybody ever tried to write a clause into the contract that they earn a specific, small proportion of the profits made from the domain name? I imagine it would have to be written in extreme detail with access to accounts etc., otherwise would be difficult to enforce? Not sure if it is practical.

Thank you.