public boolean buttonAction(String actionCommand) {
		if (actionCommand.equals("Start")) {
			startAction();
		} else if (actionCommand.equals("Stop")) {
			stopAction();
		} else if (actionCommand.equals("Step")) {
			stepAction();
		} else if (actionCommand.equals("Call")) {
			callAction();
		} else {
			return false;
		}
		return true;
	}