You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I render you?

USER: Can you book a flight ticket on my name Ryan Campbell, to reach Las Vegas?

ASSISTANT: Sure, I am happy to serve you.

USER: Thank you.

ASSISTANT:  Can you please forward your take off airport code?.

USER: It is a round-trip to LAS.

ASSISTANT: Please share your itinerary dates?

USER: My itinerary dates are on 10/18 and 10/20.

ASSISTANT: Do you have any other requirements?

USER: I need a connecting flight, and fare must be within 200.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting, we are sorry to inform you that no flights were available based on your schedule.

USER: Ok, Thanks for your information.

ASSISTANT: Thank you for choosing us.