You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I need to buy a plane ticket. Please help me with that.

ASSISTANT: Sure, may I know your source and destination airport codes?

USER: My source airport code is BOS  and destination airport code is AUS.

ASSISTANT: Let me know your travelling dates.

USER: My travelling dates are from Jan, 04 to Jan, 06.

ASSISTANT: Is there any class preference?

USER: I need an economy class to fly.

ASSISTANT: Do you have any other requirements?

USER: I prefer a single connecting flight and I need to travel in normal-cost airlines.

ASSISTANT: May I know your name please?

USER: I am Dennis Carter.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for opting us.