You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I need to change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Sure, I am here to help you with that. May I know your name please?

USER: Thank you for considering my request. Myself Timothy Brown.

ASSISTANT: Please wait for a while, let me check your previous reservation status.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, as per your concern I can not amend your reservation, as your reservation is not found as per our records.

USER: Not an issue, anyway thank you for the information.

ASSISTANT: Welcome, thank you for reaching us.

USER: Thank you for your service.