You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

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

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Can I have your good name please to check your reservation status?

USER: Previous reservation was done under the name of Larry Wilson.

ASSISTANT: Ok, please wait a moment.

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

ASSISTANT: Sorry Larry Wilson, no reservation has found under your name to change.

USER: Ok, not a problem. Anyways, thank you.

ASSISTANT: Thank you for choosing us, have a good day.