You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Samuel Young. I want to change an existing reservation, due to my health issues.

ASSISTANT: Sure, please wait a minute.

USER: Sure.

ASSISTANT: Thank you for your time. Unfortunately there is no reservation found by your name.

USER: Not an issue. Thank you for your service.

ASSISTANT: Thank you for reaching us.