You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Richard Perez.

ASSISTANT: Richard Perez. How can I help you?

USER: I planned to meet my cousin in IAD, can you please help me to book a flight ticket from LAS?

ASSISTANT: Please provide me with the travel dates.

USER: I prefer to travel on Aug 20 and Aug 22.

ASSISTANT: Do you have any preferences?

USER: I prefer to travel in 1 connecting flight and depart in afternoon.

ASSISTANT: Sorry to inform that, there are no flights for your desired dates.

USER: Ok, no problem.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your information.