You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Due to my health problems, I would like to change my existing reservation. Please help me out.

ASSISTANT: Sure, can I know your name please?

USER: My name is Gary Scott.

ASSISTANT: Ok, wait a moment please.

USER: Sure, take your time.

ASSISTANT: Sorry Gary, there is no reservation found on your name.

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

ASSISTANT: Thank you for approaching us.