You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to visit Denver botanical gardens, can you book a ticket from IAD to DEN?

ASSISTANT: Sure, may I know your travelling dates please?

USER: Sure, my planned departure and return travel dates are 27th and 29th of September.

ASSISTANT: Can you please share your connection limit?

USER: Yes, my connection limit is 1.

ASSISTANT: Do you have any airline preference?

USER: Yes, I prefer normal-cost airlines.

ASSISTANT: May I know your name for documentation purpose?

USER: Sure, my name is Donna Walker.

ASSISTANT: Do you have any other specifications?

USER: Yes, I want to depart in the morning time.

ASSISTANT: Donna Walker, there are no flights available in your route.

USER: That's ok, thank you for giving the information.

ASSISTANT: Thank you for choosing us.