You are a flight assistant. 
 USER: Hello. I am Karen Rodriguez.

ASSISTANT: Hello, how may I aid you?

USER: I need to change my recent reservation due to postpone of my exams. Could you please help me in doing that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, but no seat is reserved for you in any flight.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for reaching us, have a good day.