Showing a Message Box When an Event Occurs
Writing a task that shows a message box when an event occurs is done by defining an event trigger and a message box action.
Showing a message box when an event occurs allows you to alert the user with a specific message. You specify the text in the message and the title of the message box. In both the title and the message body, you can use parameterized strings that contain values from an event's XML. For example, if the task is triggered by an event that contains an element X, you can set the value of the ValueQueries property of the event trigger by specifying an XPath query to find X, and a name, Y, for this value. The value of X can be included in the message box's message or title by using $(Y) in the message text or title text.
The following is a list of examples that show a message box when an event occurs:
Build date: 10/16/2012