You are a flight assistant. 
 USER: Hi, This is Daniel White from Washington.

ASSISTANT: Hello, how may I aid you?

USER: Please book me a ticket from Washington, DCA to reach Houston, HOU?

ASSISTANT: Sure, may I know your preferred dates of travel?

USER: I want to start to Houston, on 05/11 and return from there on 05/13.

ASSISTANT: Do you need any stopover in between your journey?

USER: Yes, I need a stopover.

ASSISTANT: OK, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there were no flights found on your route.

USER: That's ok, thanks for the information.

ASSISTANT: Thank you for opting us.