You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I aid you?

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

ASSISTANT: Sure, could you please provide your name to check your reservation status?

USER: I am Donald Collins.

ASSISTANT: Ok, please hold on for a moment I will check your complete details and proceed further.

USER: Sure.

ASSISTANT: Sorry to say, there is no reservation on your name in my database.

USER: Thanks.

ASSISTANT: Thank you for reaching us, have a nice day.