You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I serve you?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your good name please?

USER: Sure, my name is Elizabeth Taylor.

ASSISTANT: Please hold on a minute.

USER: Sure, take your time.

ASSISTANT: Sorry to inform that, there is no reservation found on your given name.

USER: That's fine. Anyways, thank you for your service.

ASSISTANT: Thanks for reaching us, have a nice day.