You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I want to book a ticket from DEN to MCO. Could you book a ticket?

ASSISTANT: Sure, may I know your name please?

USER: My name is Emily Wright.

ASSISTANT: May I know on which dates you are willing to travel?

USER: Departure is Aug, 28 and return date is Aug, 30.

ASSISTANT: May I know your class preference please?

USER: I would like to prefer business class.

ASSISTANT: May I know your preferable time for journey?

USER: I would like to return in the evening time.

ASSISTANT: Sorry Wright, there is no flight found as per your travelling dates.

USER: Thank you.