You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I would like to spend some more days with my family, please help me in changing my existing reservation.

ASSISTANT: Sure, I can help you with that. May I know your good name please?

USER: My name is Lisa Evans.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Lisa Evans, there is no active reservation found under your name to do modifications in that.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for choosing us.