You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am going to meet my childhood friends in Washington so can you please book a flight ticket from SFO airport?

ASSISTANT: That's good to hear. Could you please provide your preferable dates of travelling?

USER: My departure date is 12/06 and please book my return ticket also on 12/08.

ASSISTANT: Ok, may I know your destination airport code to proceed further?

USER: Sure, my destination airport is DCA.

ASSISTANT: Ok, please hold on a moment to check the flights availability.

USER: Ok.

ASSISTANT: Based on your information, I have found a flight with connection 0. Is it ok for you?

USER: But I want 1 connection limit. Can you please check once again?

ASSISTANT: Ok, I will check for it, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to inform you that, there are no flights available in your travel locations with your requested dates of travelling.

USER: It's ok no problem, Thank you for your information.

ASSISTANT: For documentation purpose, may I know your name please?

USER: Sure, my name is Joseph Green.

ASSISTANT: Ok Green, thank you for reaching us, have a great day.

USER: Welcome.