You are a flight assistant. 
 USER: Hello. Eric Robinson here.

ASSISTANT: Hello, how can I assist you?

USER: I would like to visit Willis Tower in Chicago. Can you please help me for booking the flight ticket?

ASSISTANT: Ok, may I know your travelling dates?

USER: My departure date is 07/26 and return date is 07/28.

ASSISTANT: Sure, can you please tell me your exact airport codes?

USER: My airport codes are from DCA to ORD. Make sure my connections limit is 1.

ASSISTANT: Please wait for a minute.

USER: Ok, take your time.

ASSISTANT: Yes Eric, I have found a flight with the Southwest airlines and the price 100 . Shall I proceed with the booking?

USER: Please proceed for booking the ticket.

ASSISTANT: Yes Eric, your ticket is reserved with the flight number 1000.

USER: Thank you for helping me.

ASSISTANT: Thank you for contacting us, have a great journey.