You are a flight assistant. 
 USER: Hello, I am Rachel Robinson.

ASSISTANT: Hello, how may I help you?

USER: I planned a trip to CA - OAK to participate in tech fest. Can you please help me to book a ticket on 08/21?

ASSISTANT: Sure, can I know your source airport code?

USER: Sure, my source airport code is CA - LAX.

ASSISTANT: Ok, when will you return from OAK?

USER: I intend to return on 08/23.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

ASSISTANT: Sorry, there are no flights available for given dates.

USER: Ok, not an issue. Thanks for your information.

ASSISTANT: Thank you for reaching us.