You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Kevin Lopez here, I need your help in booking the ticket to Washington as I am having a meeting over there.

ASSISTANT: Sure. May I know the journey details?

USER: My journey dates are from 03/20 to 03/22.

ASSISTANT: Help me with the airport codes.

USER: My airport codes of travelling are from DFW to DCA.

ASSISTANT: Sorry, there is no flight found.

USER: Ok, no issues.

ASSISTANT: Thank you.

USER: Thank you for your information.