You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

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

ASSISTANT: I understand your request and will be happy to help you. Could I have your name please?

USER: My name is Barbara Smith.

ASSISTANT: Sorry, there is no reservation matching with your name in our portal to make changes further.

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

ASSISTANT: Thank you for consulting us, hope you choose our agency for your future ventures.