You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I want to book a direct flight ticket to Oakland, can you help me?

ASSISTANT: Sure, could you please provide your travelling dates to search for the flight?

USER: My travel dates are 05/18 and 05/20.

ASSISTANT: Ok, may I know the codes of airport you want to travel?

USER: My airport codes are from BOS to OAK.

ASSISTANT: Ok, please hold on for a moment.

USER: Sure.

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

USER: No problem.

ASSISTANT: May I know your name for documentation purpose?

USER: My name is Angela Jones. Thank you for checking.

ASSISTANT: Thank you for choosing us, have a nice day.