You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I'm Ruth Nelson, want to travel from IAD to DFW.

ASSISTANT: May I know your travelling dates?

USER: My travelling dates are from 07/29 to 07/31.

ASSISTANT: Sorry Nelson, there is no flights available as per your requested dates.

USER: That's fine. Thank you for your time.

ASSISTANT: Most welcome.