You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Susan Turner. I need your help in booking my flight ticket from DCA to HOU. Can you please do that for me?

ASSISTANT: Sure, may I know your trip dates?

USER: Sure, I want to depart on 10/16 and return on 10/18.

ASSISTANT: Sorry, there is no flight available as per your request.

USER: Not an issue, anyway thank you for checking.

ASSISTANT: Most welcome.