You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Thomas Walker, can you please help me to change my reservation?

ASSISTANT: Sure, please wait for a moment to check.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found on your name.

USER: Ok, thank you for providing information.

ASSISTANT: Thank you for reaching us, have a nice day.