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 happy to help you. May I know your good name?

USER: Robert Taylor here.

ASSISTANT: Sorry, there is no active reservation on your name in our records.

USER: No problem, thanks for the information.

ASSISTANT: Thank you for contacting us.