You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I would like to do some changes in my existing reservation, can you help me in that?

ASSISTANT: Can I know your name?

USER: Sure, the ticket has been reserved on the name Timothy Adams.

ASSISTANT: Sorry, no reservation found by your name.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you.