You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I need to change my current reservation due to urgent meeting, can you help me with that?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your good name please?

USER: I am David Anderson.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation found on your name to change.

USER: That's ok. Thank you for your service.

ASSISTANT: Thank you for reaching us.