You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you?

USER: I want to change my reservation, because my trip was postpone due to some problems, can you please change my reservation?

ASSISTANT: May I know your name?

USER: Sure, my name is Emily Parker.

ASSISTANT: Sorry Emily, there is no previous reservation found with your name.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: Most welcome.