You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am planning to book a flight ticket to LAS from ORD, can you please help me out?

ASSISTANT: Sure, on which dates you are planning to travel?

USER: Sure, my planned travelling dates are Aug 10 and 12.

ASSISTANT: May I know your name?

USER: Sure, my name is Paul Clark.

ASSISTANT: Ok. Sorry, on these dates there is no flights available.

USER: Ok, thank you.

ASSISTANT: Most welcome.