You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to change my existing reservation, because I have another important work on that dates, can you please help me?

ASSISTANT: Sure, please provide me your name to check the reservation status.

USER: Sure, my name is Shirley Campbell.

ASSISTANT: Please wait a minute, Shirley.

USER: Ok.

ASSISTANT: Shirley, there is no reservation found with your details.

USER: Oh it's ok no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us, have a good day.

USER: Welcome.