Based on the above case study, create a UML case diagram to illustrate the functionalities of the system.

Mewah Ticket Company is an international company with a ticketing system from which tickets for major events such as musical concerts, theater, and sports events can be purchased over the phone. It employs many agents to answer call inquiries concerning dates and locations, and in most cases, results in the caller purchasing tickets. When a customer calls an agent to purchase tickets to an event, the agent will ask the caller for the name of the event, its location, and preferred dates. Once the caller provides this information, the agent informs the caller if seating is available for the requested show and the available ticket prices. The caller then selects the ticket price and the number of seats. The agent locates the required number of seats and holds them temporarily so they cannot be taken by another agent. The agent informs the caller of the viewing angle of the seating such as from the left side, front or back of the stage. The caller decides on the section and confirms the number of tickets. The agent collects payment information from the caller such as cardholder name, credit card number and expiration date. After receiving the credit transaction authorization from the card issuer, the agents confirm the ticket purchase and gives the confirmation number to the caller. If the sale does not complete due to bad credit, the seats are released, otherwise the seats are sold. If the credit card system is not operational, the seats are held, and the sales transaction will be completed later. All sales are final. The customer and agent agree on either having the tickets mailed directly to the customer's address or held at the "will- call" box of the performance location