You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you today?

USER: Paul Smith here. Can you please help me in booking a flight ticket from DCA to JFK?

ASSISTANT: Sure, please provide your travelling dates.

USER: Sure, my travel dates are from Feb 02 to Feb 04.

ASSISTANT: Ok, may I know your class preference?

USER: I am comfortable with any class.

ASSISTANT: Ok, do you have any specifications?

USER: I would like to return in evening.

ASSISTANT: Ok, do you need any break in between the journey?

USER: No, I am ok with any flight.

ASSISTANT: Ok, please wait for few minutes.

USER: Sure, take your time.

ASSISTANT: There are no flights found on your requested dates.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.