How would you add a modify event on an object  like what is in AutoCAD's DBObject? What does DraftSight call an object in the API?

I am trying to find out if a polyline is modified:

public void dsPolyline_Modified(object sender, EventArgs e)

{

Document dsDoc = dsApp.GetActiveDocument(); dscommandMessage = dsApp.GetCommandMessage();

if (dscommandMessage == "ERASE" && dsPolyLine.Erased)

{

try

{

dsPolyLine.Modified -= new EventHandler(dsPolyline_Modified);

//In AutoCAD I can unhook the event if a polyline object is modified, how is it possible in DraftSight?

}

catch (Exception) { }

}

}