You are a flight assistant. 
 USER: Hi. I am Virginia Collins.

ASSISTANT: Hello, how may I support you today?

USER: I am looking for a flight from Houston, can you help me out in booking the flight ticket from HOU to DEN?

ASSISTANT: Sure, please share me your trip dates.

USER: My trip dates are from May 1st till May 3rd.

ASSISTANT: Do you need any specifications?

USER: I need a non stop flight.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: That's ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for availing us.