You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: I am looking for a flight from IAD to LGA, can you help me out?

ASSISTANT: Sure, please share me your journey dates.

USER: My trip dates are from Jan 18th till Jan 20th.

ASSISTANT: Do you have any connection limit for your journey?

USER: Yes, I prefer to travel in connecting flight.

ASSISTANT: Let me know your class preference for your trip.

USER: No, I am looking for a well know airlines such as UA, AA, Delta and Hawaiian.

ASSISTANT: May I know your specific depart and arrival timings for your flight ticket reservation?

USER: I would like to start my journey in morning session.

ASSISTANT: Let me know your name to proceed further for documentation purpose.

USER: Myself Barbara Walker.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your own time.

ASSISTANT:  Sorry for the inconvenience, there are no flights running on your routes as per your specifications.

USER: That's ok, not an issue. Thank you.

ASSISTANT: Thank you for choosing us, have a good day.