You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I would like to book a flight from LAX to LAS, can you please help?

ASSISTANT: Sure, let me know your planning dates to travel.

USER: My travel dates are July 31st and Aug 2nd.

ASSISTANT: Which class would you like me to choose?

USER: I prefer to fly in the economy class.

ASSISTANT: Ok, do you have any preference in connection?

USER: Yes, I prefer maximum one connection.

ASSISTANT: May I know the time concern please?

USER: I want to depart in the evening time and return back in the morning time.

ASSISTANT: Please share me your name to proceed further.

USER: My name is Joseph Hall.

ASSISTANT: Sorry, unfortunately no flights are available on your desired route.

USER: Not a problem, thank you for your help.

ASSISTANT: Thank you for reaching us.