You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER:  Due to some entrepreneurship meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: Sure, I am here to help you out. Please provide me your provide me your name to check whether any active reservation is found on your name or not.

USER: I am Jack Walker.

ASSISTANT: Please allow me a moment.

USER: Sure.

ASSISTANT: Sorry Jack Walker, there is no active reservation on your name in our database.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us Jack Walker.