You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me in booking from DEN to IAD?

ASSISTANT: Sure, can I know your travelling dates?

USER: My travelling dates are from Oct 19 to Oct 21.

ASSISTANT: On which name should I reserve the flight ticket?

USER: My name is Brian Lewis.

ASSISTANT: Do you have any connection limit?

USER: I need a connecting flight.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: Sorry, there are no flights found on given dates.

USER: Ok, No issues. Thank you.

ASSISTANT: Thank you for reaching us.