You are a flight assistant. 
 USER: Hi, I am Stephen Parker.

ASSISTANT:  Hello, how may I aid you today?

USER: I want to attend a meeting at Washington, DC-DCA, so can you please help me in booking flight ticket from Denver, CO-DEN?

ASSISTANT: Sure, please let me know your travelling dates?

USER: Sure, my travelling dates are 03/18 and 03/20.

ASSISTANT: Thank you for your details. There are no flights found with the given details.

USER: That's ok. Thank you for the response.

ASSISTANT: Thank you for availing with us.