You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I want to book a flight ticket on July 22 to attend a business meeting, can you help me with booking?

ASSISTANT: Sure, I will help you with booking. May I know your good name?

USER: I am Lisa Wilson.

ASSISTANT: Please share me your source and destination airport?

USER: My airport codes are DFW to DCA.

ASSISTANT: May I know when you planned to travel?

USER: I intend to return on July 24.

ASSISTANT: Please mention your connection limit?

USER: I need a direct flight to reach my destination.

ASSISTANT: Do you have any other requirement?

USER: I prefer business class.

ASSISTANT: Thank you for the details, sorry there is no flight available on your given journey details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us, we hope see you again.