You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: Owing to an emergency, I just want to change my existing reservation. Can you help me to change it?

ASSISTANT: Sure, may I know your name?

USER: Sure, my name is Shirley Allen.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there was no reservation found on your name.

USER: Ok, thanks for your help.

ASSISTANT: Thank you for choosing us.