You are a flight assistant. 
 USER: Hello. I am Steven Lewis.

ASSISTANT: Hello, how can I assist you today?

USER: I wish to go for Hop-on Hop-off trolley tour at Boston, BOS. Can you please book a direct flight for me?

ASSISTANT: Sure. Let me know your boarding airport code.

USER: Source point is Oakland, OAK.

ASSISTANT: How much you can afford for this journey?

USER: Price limit is 1000.

ASSISTANT: Help me with your travelling dates to proceed further.

USER: Trip dates are 02/10 to 02/12.

ASSISTANT: Thank you for waiting. Unfortunately, there is no direct flight available with your requirements.

USER: No problem. Thank you.

ASSISTANT: Thank you for opting us.