You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I assist you?

USER: Owing an emergence, I want to change my existing reservation.

ASSISTANT: Sure, I will help you. May I know your name please?

USER: My name is John Davis.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Thank you for being on hold, We are sorry to inform you that there is no reservation found with your name.

USER: Ok, no issues.

ASSISTANT: Thank you for availing us.

USER: Thanks for the help.