You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

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

ASSISTANT: Sure, I very glad to help you with that.

USER: Thank you for considering my request.

ASSISTANT: May I know your name please.

USER: Sure, my name is Ruth White.

ASSISTANT: Sorry, there is no reservation found on your name in our records.

USER: Ok, no problem.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your appreciable service.