You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Kevin Hernandez. I am planning to visit BOS to meet my sister, can you please find a flight from SFO?

ASSISTANT: May I know your travelling dates?

USER: My trip dates are from 09/15 till 09/17.

ASSISTANT: Sorry, no flights found on your preferable dates.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.