
if(dialog_list[VrmlTypes.Anchor] == null)
dialog_list[VrmlTypes.Billboard] =
new BillboardDialog(parent, screen_data, vrml_data);
to
if(dialog_list[VrmlTypes.Billboard] == null)
dialog_list[VrmlTypes.Billboard] =
new BillboardDialog(parent, screen_data, vrml_data);