You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: Will you please help me to book a flight ticket from LAS to PHX?

ASSISTANT: Sure, May I know the travelling dates?

USER: I will start on Aug, 18 and return on Aug, 20.

ASSISTANT: Do you have any connection limit?

USER: I would prefer single connection.

ASSISTANT: Is there any other requirements?

USER: I need to travel in economy class.

ASSISTANT: May I know your name?

USER: My name is Barbara Carter.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for opting us.