You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Rebecca Anderson. I want to book a ticket from ATL to ORD.

ASSISTANT: May I know your travelling dates please?

USER: My preferable dates are from 07/28 to 07/30.

ASSISTANT: Sorry, there are no flights available as per your request.

USER: That's ok , no problem. Thank you for helping me.

ASSISTANT: Most welcome.