You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you now?

USER: I want to change my existing reservation owing to an emergency.

ASSISTANT: Sure, I will help you with that. May I know your name please?

USER: My name is Donald Thomas.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: Thank you.

ASSISTANT: Thank you for reaching us, we hope see you again.