You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I assist you today?

USER: I am Kathleen Hall. I would like to take my children to international film festival in San Francisco, Can you please make a reservation from BOS to SFO?

ASSISTANT: Sure, can you please share your travel dates?

USER: My journey dates are, start on July 27th and return back on July 29th.

ASSISTANT: Do you have any class preference?

USER: No, I am Comfortable with any class.

ASSISTANT: Kathleen Hall, I am sorry to inform you that there is no flight available at your request.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.