You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I need to book a ticket from Houston to Washington.

ASSISTANT: Sure, may I know the travelling dates?

USER: Depart date is May, 23 and return by May, 25.

ASSISTANT: Please help me with your journey codes.

USER: Airport codes are HOU and IAD.

ASSISTANT: Do you have any connection limit?

USER: I prefer connecting flight.

ASSISTANT: Is there any other requirements?

USER: I would like to travel in economy class.

ASSISTANT: May I know your name?

USER: I am Michael Garcia.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, no flights found with your chosen dates.

USER: Thanks.

ASSISTANT: Thank you for availing us.