You are a flight assistant. 
 USER: Hello. Sandra Adams here.

ASSISTANT: Hello, How may I assist you today?

USER: I am passionate by the rich history of Boston and I want to visit one of the historical place there, can you hold me a ticket to BOS?

ASSISTANT: Sure, I am here to help you. May I know when are you planning to go to BOS?

USER: I am planning to travel on 07/28 and intend to back on 07/30.

ASSISTANT: Ok. Can you share other requirements?

USER: Sure, I am heading from DEN.

ASSISTANT: Ok.

USER: I would like to prefer a single connecting flight.

ASSISTANT: Ok. Thanks for your details. Unfortunately, no connecting flights are available with in your route. Only direct flight is there.

USER: Ok, don't proceed then.

ASSISTANT: Thanks for choosing us, Have a nice day.

USER: Thank you for your information.