You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I help you?

USER: Please change my existing reservation owing to an emergency.

ASSISTANT: Sure, can I have your good name please?

USER: I am Thomas Miller.

ASSISTANT: Please be on hold, I'll revert you back.

USER: Ok.

ASSISTANT: There is no reservation found under your name to do changes in that.

USER: Thank you.

ASSISTANT: Thank you so much for choosing us.