You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I'm Sarah Williams. I am planning to attend music concert at SFO, can you please help me with booking a flight ticket from DFW?

ASSISTANT: Sure, can I know your travel dates?

USER: Sure, I would like to take off on 10/19 and return back on 10/21.

ASSISTANT: Please give me a minute.

USER: Sure.

ASSISTANT: Sarah, there is no flight available on your requested dates.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: You are welcome.