You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation as I am no issued with leave on that particular dates. Please help me out.

ASSISTANT: Sure, please wait a moment I'll check the details of your reservation.

USER: Ok.

ASSISTANT: May I know your name for further proceedings?

USER: I am James Hill.

ASSISTANT: Sorry James, I didn't found any details regarding your reservation.

USER: No problem, thank you for the information.

ASSISTANT: Thanks for approaching us. Have a nice day!.