You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you?

USER: I want to book a flight ticket from HOU to DCA, can you please help me in flight booking?

ASSISTANT: Sure, when are you planning to make your trip?

USER: I want to fly on June 17, return on June 19.

ASSISTANT: Is there any class preference?

USER: I want economy class flight ticket.

ASSISTANT: How many number of connections are you looking for?

USER: I want a flight with one connection.

ASSISTANT: Do you have any other specifications?

USER: My depart time should be evening.

ASSISTANT: May I know your name?

USER: My name is Helen Lewis.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting Helen Lewis, there are no flights available for you matching your credentials.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.