You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my existing reservation due to some health issues, can you help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please share your name to check on current reservation.

USER: I am George Carter.

ASSISTANT: There is no reservation found on your name to change.

USER: No problem, thank you for the information.

ASSISTANT: Thank you.