designs, or symbols or in any modified form as part of any corporate or trade name nor shall Franchisee use any Mark in connection with the sale of any unauthorized product or service or in any other manner not expressly authorized in writing by Pretzel Time. 6.D. TERMINATION. Immediately upon the termination of this Agreement, the Franchisee agrees to cease and forever abstain from using the Pretzel Time trade name and Marks and return to Pretzel Time all documents, manuals, instructions, display items and the like bearing the aforesaid trade names or any of the Marks. 6.E. TRADEMARK ENFORCEMENT. Pretzel Time shall police and enforce its rights with respect to its trademarks and other proprietary aspects of the Pretzel Time System with the cooperation of Franchisee, and shall bring appropriate actions or proceedings against infringers or other unlawful users at its sole expense. Franchisee agrees to immediately notify Pretzel Time of any claim, demand or suit based upon or arising from or of any attempt by any other person, firm or corporation to use Pretzel Time's trademarks, service marks, copyrights, trade secrets, or Systems licensed hereunder or colorable variation thereof in which Pretzel Time has a proprietary interest. Pretzel Time will take the action it thinks appropriate. In the event Pretzel Time undertakes any prosecution of litigation or defense relating to the proprietary Marks licensed hereunder, Franchisee agrees to execute any and all documents and do such acts and things as may in Pretzel Time's opinion, be necessary to carry out such defense or prosecution. Franchisee agrees that Pretzel Time has the right to control administrative proceedings or litigation with respect to this issue. Franchisee agrees to participate and cooperate in the prosecution of any action to prevent the infringement, imitation, illegal use or misuse of the Marks and agrees