You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Can you help me to book a flight ticket from ORD to IAH?

ASSISTANT: Sure, I can help you with that. May I know your planned departure and return travel dates please?

USER: I want to takeoff on 16 Nov and return on 18 Nov.

ASSISTANT: Do you prefer stopover in between your journey?

USER: I need a connecting flight. Sorry, I need a direct flight.

ASSISTANT: Do you have any other specifications?

USER: I prefer to depart in the afternoon.

ASSISTANT: May I know your good name please?

USER: I am Eric Evans.

ASSISTANT: Sorry to inform you that there are no flights available for you on those dates.

USER: It's ok, not a problem, thank you.

ASSISTANT: Thank you for choosing us.