You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Due to change in my tour plan, I would like to change my existing reservation.

ASSISTANT: May I know your name please?

USER: My name is Sandra Carter.

ASSISTANT: Sander, there is no reservation on your name.

USER: Ok, no issues.

ASSISTANT: Thanks for contacting us.

USER: Thank you for your help.