You are a flight assistant. 
 USER: Hello, I am Nicholas Carter.

ASSISTANT: Hello.

USER: I need to travel in a direct flight. Could you please help me with booking a flight ticket?

ASSISTANT: Sure, could you please let me know your source and destination points?

USER: My source is MA-BOS and destination is CO-DEN.

ASSISTANT: May I know the planned travelling dates?

USER: Sure, 03/15 and 03/17 are my travelling dates.

ASSISTANT: Is there any fare limit?

USER: I can pay up to 500.

ASSISTANT: Thanks for sharing your journey details, unfortunately there are no flights found with your essential details.

USER: No problem,thank you for the information.

ASSISTANT: Thanks for contacting us.