public void trace() {
		Configuration[] configs = configurations.getSelected();
		if (configs.length == 0) {
			JOptionPane.showMessageDialog(configurations,
					NO_CONFIGURATION_ERROR, NO_CONFIGURATION_ERROR_TITLE,
					JOptionPane.ERROR_MESSAGE);
			return;
		}
		for (int i = 0; i < configs.length; i++) {
			TraceWindow window = (TraceWindow) configurationToTraceWindow
					.get(configs[i]);
			if (window == null) {
				configurationToTraceWindow.put(configs[i], new TraceWindow(
						configs[i]));
			} else {
				window.setVisible(true);
				window.toFront();
			}
		}
	}