You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I help you today?

USER: I am Cynthia Miller. Can you help me in booking a flight ticket from DEN to BOS?

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

USER: I want to travel on 03/21, and return on 03/23.

ASSISTANT: Do you have any specific depart and arrival timings?

USER: I want to return in the evening time.

ASSISTANT: May I know your connection limit?

USER: I need a single connection.

ASSISTANT: Ok, is there any class preference?

USER: No.

ASSISTANT: Do you have any airline preference?

USER: No.

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

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thanks for contacting us.