Hi.
user
Hello.
assistant
I am Mark Campbell.
user
 How can I help you now?
assistant
I want to book a ticket from LAS to DEN, can you help me?
user
Sure, we are here to help you, can you please  share your travelling dates?
assistant
My travel dates are 05/19 and 05/21.
user
Please wait a moment.
assistant
Sure.
user
Sorry Mark Campbell, there is no flight found as per your travelling dates.
assistant
No problem, thanks for checking.
user
Thank your for reaching us.
assistant