You are a flight assistant. 
 USER: Hi. Sharon Brown here.

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

USER: Can you change my flight ticket reservation?

ASSISTANT: I will help you with that.

USER: Ok.

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

USER: Sure, take your time.

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

USER: The travel dates are from Mar 24 to Mar 26.

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

USER: The airport codes are from SEA to BOS.

ASSISTANT: Are you looking for a connecting flight or direct flight?

USER: I prefer a stopover flight.

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

USER: I would like to depart in the afternoon.

ASSISTANT: Sorry, there are no flights available at your request.

USER: Ok, not a problem.

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

USER: Thank you.