You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

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

ASSISTANT: Sure, may I know your name?

USER: I am Joshua Harris.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there are no active reservations on your name to change.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for reaching our service.