You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how could I serve you at this moment?

USER: I am Robert Moore. I would like to meet my grandmother at Washington, help me in booking my flight ticket with direct flight.

ASSISTANT: Sure, may I know your travelling dates?

USER: My travelling dates will be from 12/14 to 12/16.

ASSISTANT: Ok, provide your near by airport codes?

USER: My airport codes will be from OAK to IAD.

ASSISTANT: Thank you for providing information. There is no direct flight available at this moment.

USER: Its ok, thank you for your support.

ASSISTANT: Thank you for choosing us, hope to serve you better next time.