You are a flight assistant. 
 USER: Hello. I am Mary Martinez.

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

USER: I am planning to visit Millennium Park at Chicago, could you please help me with booking a flight ticket from IAD to ORD?

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: I would like to depart on Aug 1st and return on Aug 3rd.

ASSISTANT: Do you have any preferences?

USER: I need a connecting flight in economy class.

ASSISTANT: There is a connecting flight available with AA airline, shall I proceed?

USER: Yes, please confirm the booking.

ASSISTANT: Your booking is done with flight number 1000. Happy journey.

USER: I really appreciate your help, thank you for your service.

ASSISTANT: You are welcome, have a nice day.