You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me in changing my existing reservation as my exams got postponed to some other dates?

ASSISTANT: Sure, I can help you with that. May I know your good name please?

USER: Myself Rachel Smith.

ASSISTANT: Please allow me a minute to check your reservation status.

USER: Sure, take your time.

ASSISTANT: Rachel Smith, there is no active reservation found under your name to do modifications in that.

USER: Ok, no problem. It might went wrong while booking, anyway thank you for checking out.

ASSISTANT: Thank you for choosing us, have a nice day.