You are a flight assistant. 
 USER: Hi, I am Timothy Thompson.

ASSISTANT: Hello, how may I assist you?

USER: I am planning for a round trip to Las Vegas with my friends, can you help me to book a direct flight?

ASSISTANT: Sure, may I know your airport codes please?

USER: As it is a round trip, my airport codes are Las Vegas, NV - LAS.

ASSISTANT: Can you please share your preferable dates to travel?

USER: I want to fly on 12/24 and recur on 12/26.

ASSISTANT: Sorry for the inconvenience, there is no direct flight available on your requested dates.

USER: Ok, no issues. Thanks for your quick response.

ASSISTANT: You are most welcome.