You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Dennis Hall. I am planning to visit Denver from HOU to SEN. Can you make a reservation for me?

ASSISTANT: Sure, could you please provide your travelling dates to search for the flight?

USER: Sure, my itinerary dates are on 03/18 and return on 03/20.

ASSISTANT: Just hold on a moment, I will check flight availability in this route.

USER: Ok.

ASSISTANT: Sorry to say, no flights were available on your route.

USER: Ok, not a problem.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thank you for your information.