Hello.
user
Hello, how can I assist you today?
assistant
 As I am a scientist, I want to attend science festival with my students at Chicago. Can you do the reservation?
user
Sure, may I know your planned travel dates?
assistant
Dates are 04/16 and 04/18.
user
May I know your source and destination codes?
assistant
My airport codes are LAS-ORD.
user
Your good name please.
assistant
Andrew Martinez here.
user
Sorry to say that, no flights were found with your given details.
assistant
No problem, Thank you for kind service.
user
Thank you for opting us.
assistant