You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jacob Nelson.

ASSISTANT: How may I guide you today?

USER: Please help me in booking from IAD to ORD.

ASSISTANT: Sure, I will help you with that. Can you please provide your travelling dates?

USER: My travelling dates are from Mar 25 to Mar 27.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: I want to return in the afternoon only.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need a connecting flight.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: We are apologize that, there are no flights running towards your region with your requested dates of travelling.

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for approaching us, hope you have a great day.