You are a flight assistant. 
 USER: Hello. I am Mary Jackson.

ASSISTANT: Hello, How can I assist you?

USER: I am planning to surprise my grandparents at Dallas, TX-DFW. Can you please help me in booking from San Francisco, CA-SFO?

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

USER: My trip dates are from 11/11 to 11/13.

ASSISTANT: Please give a minute.

USER: Ok.

ASSISTANT: Sorry, No flights found with your preferable dates. Thank you for choosing us.

USER: Ok, thank you.