You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I would like to change my existing flight reservation that has been booked earlier this week.Could you please help me in re-modifying my dates in the reservation?

ASSISTANT: Sure, can I know your name?

USER: Myself Raymond Thompson.

ASSISTANT: Please wait for a while.

USER: Sure, take your time.

ASSISTANT: Raymond, there is no active reservation found with your name in our records.

USER: That's fine, thank you.

ASSISTANT: Most welcome.