You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jonathan Green, can you book a flight ticket from SEA to DCA?

ASSISTANT: Sure Jonathan, can I know the dates you are intrested to travel?

USER: From 09/03 to 09/05.

ASSISTANT: I am sorry to inform you that there are no flights on your required dates.

USER: No problem. Thank you.

ASSISTANT: Thank you, have a good day.