You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Justin Martin.

ASSISTANT: How may I guide you today?

USER: Can you help me in changing my recent reservation, as my exam is postponed?

ASSISTANT: Sure, I will help you with that. Please wait for a minute, I will check it.

USER: Sure.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: That's ok, thank you.

ASSISTANT: Thank you for contacting us, have a great day.