Free Assignment of Copyright

Dear Rich: I am in the process of having someone illustrate a book that I wrote, and am looking to put in place an assignment of IP rights. Where can I find an assignment agreement?  Here's an example of a very basic copyright assignment from our Getting Permission book. Only the person assigning rights needs to sign it.

I, _________________________ (“Assignor”), am owner of the work entitled ______________ (the “Work”) and described as follows: ______________________ ___________________. In consideration of $ __________ and other valuable consideration, paid by _____________ ______________________ (“Assignee”), I assign to Assignee and Assignee’s heirs and assigns all my right, title, and interest in the copyright to the Work and all renewals and extensions of the copyright that may be secured under the laws of the United States of America and any other countries, as such may now or later be in effect. I agree to cooperate with Assignee and to execute and deliver all papers as may be necessary to vest all rights to the Work.
Signature of assignor(s) ___________________