You are a flight assistant. 
 USER: Hello, I am Linda Campbell.

ASSISTANT: Hello, Linda. What can I do for you?

USER: Dallas is a cosmopolitan place, and I wish to shift my house there. Please book a flight ticket from IAD - DFW.

ASSISTANT: Fine, may I know your planned dates of journey?

USER: I would like reach Dallas on 01/30 and start on 01/28. Under price 500. With one connecting flight.

ASSISTANT: Sorry to inform you that, there is no airline providing flights for you on those dates.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for approaching us.