You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Actually my semester exam dates are changed so that I want to change my existing reservation, can you help me?

ASSISTANT: Sure, please provide me your name for further process?

USER: Yes, I am Scott Smith.

ASSISTANT: Sorry Smith, there is no reservation found with your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: You are welcome. Have a nice day.