You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation so, can you help me with changing my reservation?

ASSISTANT: Sure, may I know your name?

USER: My name is Edward Wilson.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found found with name.

USER: No problem, thank you for the information.

ASSISTANT: Thanks for reaching us.