You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I address you today?

USER: I need to change my existing reservation as my examinations got postponed.

ASSISTANT: Sure, may I know your name?

USER: Joshua Thomas is my name. Ok.

ASSISTANT: Ok, give me a minute.

USER: Ok.

ASSISTANT: There is no reservation found by this name.

USER: Thank you for your information.

ASSISTANT: Thanks for picking us.