You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

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. May I know your name?

USER: Gregory Nelson here.

ASSISTANT: There is no reservation found with your name.

USER: No problem, thanks for the information.

ASSISTANT: Thank you for opting us.