You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I aid you?

USER: Will you help me in changing my existing reservation as my exams are postponed?

ASSISTANT: Sure, I will check with the records. May I know your name?

USER: I am James Smith.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation is existed with records.

USER: Ok, no issues.

ASSISTANT: Thank You.

USER: Thank you for prompt service.