You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER:  I am Nicholas Green want to change my reservation owing an emergency meeting. Can you please change my reservation?

ASSISTANT: Sure, We are here to help you.

USER: Thank you.

ASSISTANT: Please wait a while.

USER: Ok.

ASSISTANT: Thanks for your time. We didn't found any reservation by this name.

USER: Ok, no issues. Thank you for your response.

ASSISTANT: Thank you for choosing us.