You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you today?

USER: I want to change my existing reservation, as my exams got postponed. Can you please help me out with it?

ASSISTANT: Sure, I am here to help you.

USER: Thank you for the response.

ASSISTANT: May I know your name please?

USER: My name is Frank Hill.

ASSISTANT: Ok, please wait for a moment.

USER: Ok, sure. I will wait for your quick response.

ASSISTANT: Sorry Hill, there is no active reservation found as per your name to change it.

USER: Ok, not a problem. Thank you for the information.

ASSISTANT: You are welcome.