You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Please help me to book a direct flight from Charlotte to attend a business meeting in Seattle.

ASSISTANT: Sure, may I know your travelling dates?

USER: I need to depart on Aug 12th and my return date will be on Aug 14th.

ASSISTANT: Ok, do you have any class preference?

USER: I need a business class ticket.

ASSISTANT: May I know your airport codes?

USER: My source point is CLT and my destination point is SEA.

ASSISTANT: May I know your good name please?

USER: I am Anna Harris.

ASSISTANT: Do you have any other specifications?

USER: I want to return in the evening.

ASSISTANT: There are no flights found on your requested dates.

USER: No issues, I'll choose any alternative. Thank you.

ASSISTANT: Thank you for reaching us.