In addition to receiving user input, a UI provides feedback by displaying messages. A message is a communication, to the user, that is displayed on the screen. Messages inform the user of system status or prompt the user to complete some action. Effective messages are clear and concise.
When you include an identification number in message text, place the number at the end of the message text, and not in the title bar or at the beginning of the text where it might decrease the user's ability to quickly read the message.