You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I want to change my reservation, can you help me with that?

ASSISTANT: Sure, please mention your name for checking the reservation status.

USER: Sure, Thomas Clark here.

ASSISTANT: There is no reservation found under your name.

USER: No problem, thank you for the information.

ASSISTANT: Welcome, have a great day.