You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I made a reservation earlier in the wrong date unknowingly. Can you please change my existing reservation?

ASSISTANT: Sure, may I know your good name please?

USER: Sure, I am Thomas Lee.

ASSISTANT: There is no reservation found on your given name.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for choosing us.