You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I have planned to visit Tilden Regional Park in Oakland, can you please help me to book a flight ticket from Boston?

ASSISTANT: Sure, could you please mention with your dates of journey?

USER: Ok, the dates of my journey are October 11th and October 13th.

ASSISTANT: Ok, may I know your respective airport codes of journey?

USER: I would like to take off from the airport BOS and I want to land at the airport OAK.

ASSISTANT: May I know your class preference please?

USER: No but I need a flight which is returning in the evening time.

ASSISTANT: Do you need any other requirements please?

USER: I prefer a single connecting flight to travel.

ASSISTANT: May I know your name please?

USER: My name is Laura Lee.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Lee, there is no flight found as per your travelling details.

USER: It's ok, not a problem with that. Thank you for your time.

ASSISTANT: You are welcome.