You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change me existing reservation due to postpone of my exams, can you help m me with that?

ASSISTANT: Sure, may I know your name to check with your details.

USER: My name is Jeffrey Campbell.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no active reservations on your name to change.

USER: No issues, thank you for checking.

ASSISTANT: Thank you for reaching our service.