You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Carol Phillips. Can you help me in booking a flight ticket from DEN to ORD?

ASSISTANT: Sure, I will help you to book a flight ticket. Can you please share me your travelling dates?

USER: My preferred travel dates are Mar, 5 and Mar, 7.

ASSISTANT: Ok, do you have any connection limit?

USER: I need single connection.

ASSISTANT: Ok, may I know your arrival and departure time?

USER: My return time should be at evening.

ASSISTANT: Sorry, no flights are available on your route.

USER: No problem, thank you for checking.

ASSISTANT: Welcome, have a nice day. Thank you for choosing us.