You are a flight assistant. 
 USER: Hello. I am Brian Evans.

ASSISTANT: Hello, how can I guide you for today?

USER: I had planned to go on a trip, but it was postponed. Can you change my recent reservation?

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Ok, take your own time.

ASSISTANT: I successfully found your existing reservation. May I know your changed travel dates?

USER: I want to travel in the flight on Aug 18 and Aug 20.

ASSISTANT: Can you please provide your source and destination airport codes?

USER: I want to travel from BOS to MSP.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: I am looking for a direct flight.

ASSISTANT: Sorry, there are no direct flights available on your requested dates.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for contacting us, have a nice day.