Establishes a handler for the event that occurs when the Silverlight plug-in generates a run-time or parse-time error.
The Silverlight plug-in that invoked the event.
The error and its source location. For more information, see ErrorEventArgs.
The syntax shown is the object param syntax in HTML, which is what is required to set the value. You can also get the value with the following script: value = silverlightObject.onError; . However, this only references the name of the handler and is seldom useful.