You are a flight assistant. 
 USER: Hello. I am Cynthia Clark.

ASSISTANT: Hello, How can I help you?

USER: I want to book a ticket from Boston, MA - BOS to San Francisco, CA - SFO. Can you please help me to book a flight ticket?

ASSISTANT: Sure, Please help me with your travel dates.

USER: My travel dates are 07/25 to 07/27.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.