Cyrider - 7:58 am on Mar 7, 2012 (gmt 0)

Just be sure that you stipulate that the product and any and all rights of and to the product,including but not limited to the copyright is yours and further that,(designers name)shall have no ownership rights or any right to distribute by any means said work in its entirety or parts there of ,without your expressed weitten permission.
A lawyer can put it in legaleeze but this will stand in most courts..
As an employee you have no rights,you are a slave.