You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Angela Collins.

ASSISTANT: Nice to meet you Angela Collins.

USER: Actually, I want to change an existing reservation, due to some health issues. Can you help out?

ASSISTANT: Sure, I can help you. Just wait for a while.

USER: Ok.

ASSISTANT: Sorry Collins, there is no reservation found with your name to change.

USER: That's fine. Thank you for your help.

ASSISTANT: You are welcome.