You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you today?

USER: I need to change my existing reservation as my exams got postponed, Can you please help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Let me know your name to proceed.

USER: Richard Jackson.

ASSISTANT: Ok, please wait for a while to check your reservation status.

USER: Sure.

ASSISTANT: Sorry, we have not found any reservation on your name in our database.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thanks for choosing us.