You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Donna Thomas. I want to book a ticket from CLT to HOU. Could you help me?

ASSISTANT: May I know your travelling dates?

USER: My preferable dates are from 01/11 to 01/13.

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

USER: That's ok, no problem.

ASSISTANT: Most welcome.

USER: Thank you for helping me.