You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I need to book a flight ticket from DCA to EWR, Can you please help me for booking?

ASSISTANT: Sure, help me with the trip dates?

USER: I would like to travel on 09/12 to return on 09/14.

ASSISTANT: May I know your name please?

USER: Sandra Parker here.

ASSISTANT: Do you  have any preferences?

USER: I need a business class.

ASSISTANT: Sorry, no flights were available at this moment.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for reaching us.