You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you help me to book a flight ticket from BOS to DEN?

ASSISTANT: May I know your travel dates?

USER: My travel dates are 26 to 28 of May.

ASSISTANT: Do you have any specifications?

USER: I need a direct flight.

ASSISTANT: May I know your good name?

USER: I am Pamela Roberts.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: Oh! that very sad to hear, thank you.

ASSISTANT: Thank you for reaching us.