You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I support you today?

USER: Due to international meeting got postpone, I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, we are mirthful to help you. May I know your name please?

USER: Eric Scott here.

ASSISTANT: Ok, Eric Scott, please wait for a minute.

USER: Ok.

ASSISTANT: Thanks for your time, we are sorry to inform you that no existing reservation has found in our database on your name.

USER: No problem. Thanks for quick reply.

ASSISTANT: Thank you for being in touch with us.