You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I am Joshua Young. As I have fallen sick suddenly due to bad weather, I would like to change my recent reservation. Can you help me?

ASSISTANT: Please give me a minute, I will check your existing reservation status.

USER: Sure, take your time.

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

USER: That's fine, thank you for your help.

ASSISTANT: Thank you for contacting us, have a nice day.