You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I abet you?

USER: Please help me to book a flight ticket with in the fare limit 500 to visit NASA space center at Washington.

ASSISTANT: Sure, may I know where are you heading to?

USER: I will start from Houston, TX-HOU to reach Washington DC-DCA.

ASSISTANT: Do you need a whistle stop in between?

USER: 08/13 and 08/15 are my planned travelling dates. I need a flag stop.

ASSISTANT: May I know your name?

USER: Ok. I am Melissa Miller.

ASSISTANT: Ok, there is an Hawaiian airline with flight number 1029 and price of 100 available on your route. Shall I proceed?

USER: That's fine, please proceed with the booking.

ASSISTANT: Your reservation has been done.

USER: Thanks for your kind service.

ASSISTANT: Thank you for opting us.