You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: I am planning to book a ticket from IAD to DFW, can you please help me out?

ASSISTANT: Sure, can you mention your travel dates please?

USER: I am travelling on these dates May 10th and 12th.

ASSISTANT: May I know your class preference?

USER: I prefer business class.

ASSISTANT: Any other requirement to be met?

USER: I need a single connected flight.

ASSISTANT: Let me know your name to proceed further?

USER: Linda Wright here.

ASSISTANT: Sorry, no flights are running on that route on your planned travel dates.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for contacting us.