You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I guide you?

USER: I would like to change my existing reservation due to postpone of my annual exams.

ASSISTANT: Sure.

USER: Could you please help me?

ASSISTANT: We are here to help you. May I know your name?

USER: I am Elizabeth Campbell.

ASSISTANT: We didn't found any reservation by this name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for choosing us.