You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, may I know your name to check the reservation status?

USER: George White.

ASSISTANT: Ok, please wait for a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name to change.

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

ASSISTANT: Thank you for reaching us.