You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at  this moment?

USER: Can you help me to change my existing reservation?

ASSISTANT: Sure, I am happy to help you with that.

USER: Thank you.

ASSISTANT: Can I  have your good name please to check your reservation status?

USER: My name is Susan Evans.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry Susan Evans, no reservation has found under your name to change.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us, have a good day.