You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Timothy Williams. I want to change my reservation, can you help me in that?

ASSISTANT: Sure, please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation with your name to change further.

USER: That's ok, thank you for your help.

ASSISTANT: You are welcome.