You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may 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, we are here to help you. May I know your name please?

USER: Sure, I am Michelle Thomas.

ASSISTANT: Sorry to inform you that there is no active reservation on your given name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thanks for reaching us.