When an exception is raised during the update operation, use the GridViewUpdatedEventArgs.ExceptionHandled property to indicate whether you handled the exception in the event handler. When this property is set to true, the exception is considered handled and is not thrown again by the System.Web.UI.WebControls.GridView control. If this property is set to false, the exception is thrown again. To determine which exception was raised, use the GridViewUpdatedEventArgs.Exception property.