You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you?

USER: Actually my Tennis Competition is postponed, so that I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, can I have your name please?

USER: Sure, I am Jack Scott.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found with your name in our database.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: You are most welcome. Thank you for choosing us.