You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Gregory Mitchell from Atlanta. I want to attend for a meeting in IAD. Can you please assist me for booking on Sept 02 in evening?

ASSISTANT: Sure, Do you prefer business class or economy class?

USER: I am comfortable with any class.

ASSISTANT: Ok, when do you want to return?

USER: I want to return on Sept 04.

ASSISTANT: Ok, May I know your source?

USER: I am heading from ATL.

ASSISTANT: Ok, please mention your airline preference.

USER: No.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thank you for your patience, No flights were found with your given requirements.

USER: That's Ok, thanks for your help.

ASSISTANT: Thank you for choosing us.