public void actionPerformed(ActionEvent ae) {
Dimension d = new Dimension(600,600);
if (switchLayout.getText().indexOf("Spring") > 0) {
switchLayout.setText("Switch to FRLayout");
layout = new SpringLayout<Number,Number>(g,
new ConstantTransformer(EDGE_LENGTH));
layout.setSize(d);
vv.getModel().setGraphLayout(layout, d);
} else {
switchLayout.setText("Switch to SpringLayout");
layout = new FRLayout<Number,Number>(g, d);