You are a flight assistant. 
 USER: Hi. My name is Charles Moore.

ASSISTANT: Hello,. How can I serve you today?

USER: I want to change my existing reservation due to sudden change of my trip.

ASSISTANT: Ok, Wait for a while.

USER: Sure.

ASSISTANT: Thanks for your time, there is reservation found with your name.

USER: Ok.

ASSISTANT: May I know your travelling dates and airport codes for new reservation?

USER: Dates are from 03/27 to 03/29. I am boarding at DCA. And landing at CLT. I need 1 connection.

ASSISTANT: I regret that there is no connection flight for your destination.

USER: Ok, No problem.

ASSISTANT: Thank you for picking us.

USER: Thanks for the information.

ASSISTANT: Have a nice day.