You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am David Rodriguez.

ASSISTANT: In what way can I help you now?

USER: I want to collect some information from library of congress at Washington, DCA. Can you book a flight ticket under the range of 200?

ASSISTANT: Fine. When you will start your journey?

USER: I will fly on 07/28.

ASSISTANT: Have any connection limit?

USER: I need a connecting flight.

ASSISTANT: Please help me with your source code.

USER: I want to start my journey from New York, LGA.

ASSISTANT: What is your return date?

USER: I will be return on 07/30.

ASSISTANT: Wait a minute, I will check and let you know the flight details.

USER: Sure.

ASSISTANT: There is a flight with price 300. Is it comfortable to you?

USER: No, do not proceed, I need a flight under price 200.

ASSISTANT: We do not have a flight with price 200.

USER: Ok.

ASSISTANT: Thank you for approaching us.

USER: Thank you.