You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I help you today?

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

ASSISTANT: May I know your good name please?

USER: I am Frank Williams.

ASSISTANT: Please give me a moment.

USER: Ok.

ASSISTANT: There is no reservation found with your given name.

USER: Thanks for the help.

ASSISTANT: Thank you for choosing us.