You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you at this time?

USER: Could you please book a flight ticket with a single connecting flight to Washington?

ASSISTANT: Sure, We are here to serve you.

USER: Thank you.

ASSISTANT: Can you please provide your origin and destination airport codes?

USER: My origin and destination airport codes are HOU and DCA.

ASSISTANT: May I know when are you planning your trip?

USER: My planned trip dates 19 Mar and 21 Mar.

ASSISTANT: Do you have any restrictions for your depart and return times?

USER: No, thanks for asking.

ASSISTANT: In which class would you like to travel?

USER: I am comfortable with any class.

ASSISTANT: May I know if you have any specific airlines preference?

USER: I would prefer to travel with a normal-cost airlines.

ASSISTANT: Sure, please share if you have any other preference.

USER: I don't have any other preferences.

ASSISTANT: We have a flight from American airlines, number 1018 and it is costing 100. Shall I proceed with the booking?

USER: Yes, proceed.

ASSISTANT: To confirm this ticket I need your name, can you please share it?

USER: Sure, my name is William Wilson.

ASSISTANT: Your ticket has been confirmed in economy class.

USER: Thank you.

ASSISTANT: Thank you for choosing us.