You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Myself Gregory Hill, will you help me in booking the flight from DCA to DFW?

ASSISTANT: Can I know your travelling dates?

USER: My travelling dates are May 21 and May 23.

ASSISTANT: Do you have any preference?

USER: I need a flight with single connection in business class which departs in afternoon time.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok, not an issue.

ASSISTANT: Thank you.

USER: Thank you for your information.