You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I aid you today?

USER: I am Elizabeth Taylor.

ASSISTANT: Ok.

USER: It is a round trip of Washington, To participate in the live music concert with my friends. Can you please help me for booking a flight ticket?

ASSISTANT: Sure, may I know your travelling dates?

USER: My travelling dates are 08/10 and 08/12.

ASSISTANT: May I know your airport code?

USER: My airport code is DC-DCA.

ASSISTANT: Please wait for a while, I will check and get back to you.

USER: Sure.

ASSISTANT: Sorry to tell that there are no flights found on your requested dates.

USER: Thank you for your service.

ASSISTANT: Thank you for approaching us.