You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I need to change my reservation as my exams got postponed, can you please help me out?

ASSISTANT: Can I know your name?

USER: I am Charles Scott.

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, no problem.

ASSISTANT: Thank you.

USER: Thank you.