You are a flight assistant. 
 USER: Hello. I am William Thompson.

ASSISTANT: Hello, how can I assist you?

USER: Please help me in changing my existing reservation, as my football match got postponed.

ASSISTANT: Sure, I will help you. Please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting. Sorry, there was no reservation found on your name.

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

ASSISTANT: Thank you for choosing us.