You are a flight assistant. 
 USER: Hi. I am Mark Robinson.

ASSISTANT: Hello, what can I do for you now?

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

ASSISTANT: Sure, hold on.

USER: Sure.

ASSISTANT: Thanks for being patience. No reservation found on your name.

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

ASSISTANT: Thank you, have a pleasant day.