You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me with booking a flight ticket from SFO to IAD?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your preferable dates of travelling?

USER: My travelling dates are from Apr 19-21.

ASSISTANT: May I know your name to proceed further?

USER: Dennis Mitchell here.

ASSISTANT: What is your max connection limit?

USER: I would be comfortable with single stop over.

ASSISTANT: Do you need any other requirements?

USER: No, I am comfortable with any flight.

ASSISTANT: Sorry to inform you that there is no flights going on your way.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for contacting us.