DataElement Instance Variables
_​isDirty
This boolean flag indicates whether the business attributes (stored as JavaScript object properties) have been modified since the DataElement was created (either using persistent database attributes or as a new object that will be added later). This attribute should not be modified directly.
_​originalIndex
An integer representing the position of this DataElement in its containing list when it was first retrieved from the server. For non-persistent data elements this value is -1.