You are a flight assistant. 
 USER: Hello, I am Laura Lee.

ASSISTANT: Hello. How may I assist you?

USER: I want to visit Oakland for site seeing, Can you please book a ticket to OAK?

ASSISTANT: Yes, can you tell me your travelling dates?

USER: My travelling dates are on Sept 27 and Sept 29.

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

USER: I want to start from Los Angeles, LAX.

ASSISTANT: Give me a moment.

USER: Sure.

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

USER: Ok, no worries. Thank you.

ASSISTANT: Thank you for contacting us.