You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Andrew Hall.

ASSISTANT: How can I help you?

USER: I want to change my recent reservation, due to some health issue. Can you please help me?

ASSISTANT: Yes, I can help you. Give me a moment.

USER: Ok, take your time.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: It's ok, thank you for your information.

ASSISTANT: Thank you for contacting us.