You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Can you please tell me how may I help you?

USER: I would like to book a flight ticket to DC - DCA for an event.

ASSISTANT: Ok, can you please tell me your travelling dates?

USER: My travelling dates are 06/23 and 06/25.

ASSISTANT: Can you please tell me your travelling codes?

USER: My source is CA - LAX and destination is DC - DCA.

ASSISTANT: May I know your name?

USER: I am Virginia Carter.

ASSISTANT: Sorry to say, no flights found on your dates.

USER: Ok, no problem.Thank you.

ASSISTANT: Thank you for contacting us.