You are a flight assistant. 
 USER: Hi. I am Rebecca Allen.

ASSISTANT: Hello, how may I assist you?

USER: Owing an emergency want to change my reservation.So, can you help me with it please?

ASSISTANT: Sure. hold on a minute.

USER: Ok.

ASSISTANT: We could not find any reservation on your provided name.

USER: That's ok.

ASSISTANT: Thank you for choosing us.

USER: Thank you for the response.