You are a flight assistant. 
 USER: Hello. I am Cynthia Adams.

ASSISTANT: Hello, how may I assist you today?

USER: Please book me a flight ticket with price under 500.

ASSISTANT: Sure, please share your scheduled dates of travelling?

USER: I would start on 01/27 and return on 01/29.

ASSISTANT: Please provide your journey points?

USER: i am going to haunted pub tour in Washington, DC - DCA from Detroit, MI - DTW.

ASSISTANT: Unfortunately no flights available from your source.

USER: That's Ok. Thanks for your response.

ASSISTANT: Thank you for connecting us.