You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know what kind of service you are expecting from us?

USER: Please help me to change my recent reservation.

ASSISTANT: Sure, we will help you. May I know your good name please?

USER: Thank you. Robert Anderson.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is no active reservation found in your name to change.

USER: Thank you for your information.

ASSISTANT: Thank you for reaching us.