You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I want to book a flight to Las Vegas for short vacation. Can you help me with booking?

ASSISTANT: Sure, may I know your name please?

USER: My name is Gregory Lewis.

ASSISTANT: May I know your travelling airport codes please?

USER: I will fly from ORD to LAS.

ASSISTANT: May I know your travelling dates please?

USER: I plan to travel on May 25 and return on May 27.

ASSISTANT: May I know your class preference please?

USER: I am fine with any class.

ASSISTANT: May I know your preferable time for journey?

USER: I want my return flight in afternoon.

ASSISTANT: May I know your connection limit please?

USER: I prefer a connecting flight.

ASSISTANT: Sorry Lewis, there is no flight found as per your travelling details.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for opting us.