You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Sure, may I know your name?

USER: My name is Joshua Evans.

ASSISTANT: Thank you. Please wait, let me check your reservation status.

USER: Sure, I will wait for your information.

ASSISTANT: Sorry, I did not find any reservation under your name in our database.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome and have a nice day.