You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Christopher Moore here.

ASSISTANT: How can I assist you today?

USER: Due to sudden change in my trip I would like to change my reservation. Could you please help me out?

ASSISTANT: Sure, please give me a moment.

USER: Sure, take your time to check.

ASSISTANT: Thank you for waiting.

USER: No problem.

ASSISTANT: Unfortunately, there is no reservation is found under your name.

USER: Oh, not a problem, I think my cousin changed my reservation. Anyways, thank you for the information.

ASSISTANT: Welcome, have a great day.