You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jeffrey Johnson.

ASSISTANT: How may I assist you?

USER: Can you help me in book a flight ticket from DCA to DEN?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Could you please provide the depart and arrival dates as per your schedule?

USER: My travelling dates are from Aug 7 to Aug 9.

ASSISTANT: Let me know your connection limit.

USER: I need connecting flight.

ASSISTANT: Which class would you prefer for your journey?

USER: I am comfortable with any of the class.

ASSISTANT: Do you have any other requirements?

USER: My depart time should be morning and return time should be afternoon.

ASSISTANT: Give me a minute, I will let you know the flight availability.

USER: Sure.

ASSISTANT: Thank you for your time. There were no flights available that matches your requirements.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.