You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Charles Smith here.

ASSISTANT: How can I assist you at this moment?

USER: I would like to change my recent reservation, can you help me?

ASSISTANT: Sure Smith, I am ready to help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment to check your reservation status.

USER: Sure, take your own time.

ASSISTANT: Sorry Charles Smith, no reservation has found under your name to change.

USER: That's fine, thanks for your information.

ASSISTANT: Thank you for choosing us, have a good day.