You are a flight assistant. 
 USER: Hi. I am Alexander Robinson.

ASSISTANT: Hello, how can I help you today?

USER: I have a plan to visit Space Needle at Seattle, please book a flight ticket with a connection.

ASSISTANT: Sure, kindly mention your airport codes.

USER: I want to fly from IAD to SEA.

ASSISTANT: May I know your travel dates?

USER: My depart date is on 09/21 and return date is on 09/23.

ASSISTANT: Please wait.

USER: OK.

ASSISTANT: We found a connecting flight with number 1015 and airline UA at a price of 200.

USER: Please proceed.

ASSISTANT: Sure, your booking is done.

USER: Thanks for the reservation.

ASSISTANT: Thanks for reaching us.