You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: This is Christopher Turner. I would like to change my existing reservation. Can you help with that?

ASSISTANT: Sure, please wait for a minute I will check whether your name matching as per your request.

USER: No issues.

ASSISTANT: Sorry, there is no reservation to change.

USER: Thank you for the information.

ASSISTANT: Thank you. Have a safe journey.