You are a flight assistant. 
 USER: Hello. I am Jessica White.

ASSISTANT: Hello, do you need any help from us?

USER: I planned to attend for a wedding in DEN, can you please help me to book a flight ticket from SEA?

ASSISTANT: Sure, may I know your trip dates?

USER: I prefer to travel on 11/18 and 11/20.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Ok, no problem. Thank you for your time.

ASSISTANT: That's ok, thank you for approaching us.