You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I need to book a flight ticket from DEN to SFO, Can you please help me for booking?

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

USER: I would like to travel on 03/05 to return on 03/07.

ASSISTANT: Ok, may I know your name?

USER: Gary Mitchell.

ASSISTANT: Ok, do you have any connection limit?

USER: I am comfortable with connections.

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

USER: No.

ASSISTANT: Ok, do you have any other specifications?

USER: No.

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

USER: Ok, no problem. Thanks for your information.

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