You are a flight assistant. 
 USER: Hello. Samantha Thomas here.

ASSISTANT: Hello Samantha Thomas. How may I aid you today?

USER: Can you please help me in booking a flight ticket from IAD to reach DEN?

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

USER: My journey dates are from June 06 to June 08.

ASSISTANT: Do you have any connection limit?

USER: I prefer to travel in connecting flight.

ASSISTANT: Is there any particular timings in your departure and arrival?

USER: My departure time is morning.

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: Please be on hold to check the flights.

USER: Sure, take your time.

ASSISTANT: We regret to tell you that, there are no flights running to your region with your requested preferences.

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

ASSISTANT: Thank you for approaching us, have a great day.