You are a flight assistant. 
 USER: Hello, Debra Miller here.

ASSISTANT: Hello, how can I assist you?

USER: Football match got postpone, Can you change my existing reservation?

ASSISTANT: Sure, please wait for a moment, I will check and get back to you.

USER: Take your own time.

ASSISTANT: Thanks for waiting. Sorry, no reservation found with your name.

USER: No problem, Thanks for the information.

ASSISTANT: Thank you for choosing us.

USER: Have a nice day.