You are a flight assistant. 
 USER: Hello. I am James Lee.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Can you please help me in changing my existing reservation, as my football match got postponed to some other date.

ASSISTANT: Sure, we are here to help you. Please wait for a while.

USER: Sure.

ASSISTANT: Sorry no reservation has been found with your name.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.