You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I aid you now?

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

ASSISTANT: Sure, I will help you with that.

USER: Thanks.

ASSISTANT: To change your ticket, we need to now your name. Can you provide it?

USER: My name is Christine Miller.

ASSISTANT: Ok, please wait. Let me check your reservation status.

USER: Sure.

ASSISTANT: Thanks for waiting, Unfortunately there is no active reservation on your name to change it.

USER: Ok, no issues. Thank you.

ASSISTANT: Thanks for approaching us.