sld_speed->signal_value_changed.connect(sigc::mem_fun(this, &TrainDialog::ui_speed_changed));
tgl_forward = dynamic_cast<GLtk::Toggle *>(get_item(widgets, "tgl_forward"));
tgl_forward->signal_toggled.connect(sigc::mem_fun(this, &TrainDialog::ui_forward_toggled));
sld_speed->signal_value_changed.connect(sigc::mem_fun(this, &TrainDialog::ui_speed_changed));
tgl_forward = dynamic_cast<GLtk::Toggle *>(get_item(widgets, "tgl_forward"));
tgl_forward->signal_toggled.connect(sigc::mem_fun(this, &TrainDialog::ui_forward_toggled));