You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you today?

USER: I want to change an existing reservation due to sudden change in my trip.

ASSISTANT: Sure, I will help you in changing your reservation. May I know your good name please?

USER: I am Laura Edwards.

ASSISTANT: Ok, please hold on, I will check our data base and get back to you.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no existing reservation found on your name.

USER: That's ok.

ASSISTANT: Thank you for availing us. have a great day.

USER: Thanks for your help.