You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I would like to spend some more days with my mother, I want to change my existing reservation. Please help me out.

ASSISTANT: Sure, may I know your name to check for the previous reservation?

USER: My name is Christine Lewis.

ASSISTANT: Ok, let me check for the previous reservation in our data base.

USER: Sure.

ASSISTANT: Christine, there is no reservation found under your name.

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

ASSISTANT: Thank you for contacting us.