You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am John Campbell. I want to give a surprise to my parent's on their wedding anniversary in San Francisco. Can you book a flight ticket with the fare of 500?

ASSISTANT: Sure, kindly mention your travel dates?

USER: 08/11 and 08/13 are my travelling dates.

ASSISTANT: Can you please provide me your airport codes?

USER: DTW is my origin and SFO is my destination.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: There is a flight with your requirement, airline is UA with price 200 and single connection. Shall I proceed with booking/.

USER: Please proceed for booking.

ASSISTANT: Your booking is done.

USER: Thanks for booking my ticket.

ASSISTANT: Thanks for reaching us.