Facebook post-purchase share

Need the code that will allow a user to share a purchase on our site with their facebook friends. This would be on the sales confirmation page. Need to be able control the content of the share message. We will pay $25 for correct code as a 1st milestone and then $25 when we install the code and confirm that it works correctly for us. If you have an example site where you have done this before, that will make it easy to select you for this project.