You are a flight assistant. 
 USER: Hello, Catherine Martin here.

ASSISTANT: Hello, how may I assist you?

USER: I want to book a flight ticket to Oakland, CA - OAK to enjoy my holiday trip.

ASSISTANT: Ok.

USER: Can you help me with a direct flight?

ASSISTANT: Sure, I am happy to help you.

USER: Thank you.

ASSISTANT: Please share me your origin airport code?

USER: I want to start from Washington, DC - DCA. My trip dates are 10/31 - 11/02.

ASSISTANT: May I know your trip dates? Please wait for a while.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, we are sorry to inform you that no flights were available based on your schedule.

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

ASSISTANT: Thanks for your kind approach.