You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I want to attend a marriage in Washington. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, can you please mention your dates of journey?

USER: My travelling dates are Jun 12 and Jun 14.

ASSISTANT: Ok, may I know your respective airport codes please?

USER: My airport codes are MSP and IAD.

ASSISTANT: May I know your class preference please?

USER: I want to travel in business class.

ASSISTANT: Do you have any other specifications?

USER: I want to return in afternoon.

ASSISTANT: Please wait for a mean while.

USER: Ok.

ASSISTANT: May I know your name please?

USER: Sure, my name is David Hall.

ASSISTANT: Sorry Hall, there is no flight found as per your travelling details.

USER: It's ok no problem. Thank you for your information.

ASSISTANT: You are welcome.