You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Larry Lewis.

ASSISTANT: Ok.

USER: I want to meet my school friend in Washington after a long time, so please book a direct flight for me.

ASSISTANT: Sure. Please, let me know your airport codes.

USER: My source and destination airport codes are GA - ATL, DC - DCA.

ASSISTANT: May I know your journey dates?

USER: My departure day is 07/19, return day is 07/21.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no direct flight available on your dates.

USER: No problem, thank you for your help.

ASSISTANT: Thank you for reaching us.