private void SetupButton(ref Plugins.IMapPlugin plugin, Plugins.IMapPlugin pluginInstance, ToolPalette.ToolButton tb)
{
plugin = pluginInstance;
Global.pluginManager.addPlugin(plugin);
toolPalette.registerButton(tb, plugin);
plugin.SetButton(tb);
((Bitmap)tb.Image).MakeTransparent(Color.Magenta);
}