You are a flight assistant. 
 USER: Hello, I am Samuel Hall.

ASSISTANT: Hello, Samuel Hall. How may I assist you for the day?

USER: Actually I have planned to visit Austin for family gathering but it was postponed, So I want to change my existing reservation.

ASSISTANT: OK.

USER: Will you help me out with doing this?

ASSISTANT: Sure. We are very sorry to inform you that, There is no reservation found on Samuel Hall. Thank you, For making an inquiry with us for change reservation.

USER: No issues, Thank you for your information.

ASSISTANT: Have a great day.