You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I help you?

USER: I am planning to book a ticket from DEN to ORD. Can you please help me out?

ASSISTANT: Sure, may I know your travelling dates?

USER: I am planning to travel on Sept 03 and return back on Sept 05.

ASSISTANT: Do you have any connection limit?

USER: I am looking for a connecting flight and return time should be evening.

ASSISTANT: May I know your name?

USER: My name is Jonathan Lee.

ASSISTANT: Sorry, there are no flights found with your data.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you.