You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Justin Smith.

ASSISTANT: How can I aid you at this moment?

USER: I am a science student in Washington university, I want to visit National Museum of Natural History for my thesis, can you help me in booking a ticket from Washington?

ASSISTANT: Sure, I will aid you with that. Could you please mention your travel dates for booking flight ticket?

USER: My travel dates are Jan 23rd and Jan 25th.

ASSISTANT: May I know your airport code names for further process?

USER: My airport codes are from IAD to AUS.

ASSISTANT: Do you have any another specifications?

USER: The class limit should be business. I need a connecting flight.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry no flights are available in this route as per your requested dates.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.