You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I aid you today?

USER: Can you help me in change in existing reservation, because I have postponed my meeting due to an emergency.

ASSISTANT: Sure, I am mirthful to help you. Let me know your good name to check your reservation.

USER: I am Gary Mitchell.

ASSISTANT: Please hold on for a moment.

USER: Ok.

ASSISTANT: I am here to say that, thee is no previous reservation found with your specified name.

USER: Ok. Thanks for sharing the information.

ASSISTANT: Thank you for approaching us.