You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Please book a ticket from BOS to DEN to go for Sports festival.

ASSISTANT: Sure, let me know your travel dates please?

USER: My travelling dates are Apr 14 and Apr 16.

ASSISTANT: May I know your connection limit?

USER: I want single connected flight.

ASSISTANT: Do you need any other preference?

USER: I prefer normal-cost airline.

ASSISTANT: Can I know your name please?

USER: I am Paul Roberts.

ASSISTANT: Sorry to inform you that there are no flight services available on your given details.

USER: Ok, Thank you for your help.

ASSISTANT: Thank you for contacting us.