You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I need to book a flight ticket from AUS to DFW, can you help me in booking a flight ticket?

ASSISTANT: Sure, may I know your planned trip dates?

USER: Sure, my scheduled dates are Nov 18 and Nov 20.

ASSISTANT: Do you have any connection limit?

USER: I prefer maximum one connection.

ASSISTANT: Any other requirements to be met?

USER: I am looking for return time at evening.

ASSISTANT: May I know your good name?

USER: Sure, David Phillips here.

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

USER: Ok, no worries at all. Thank you for your assistance.

ASSISTANT: Thank you for reaching us.