FormWizard: Advanced (?) CSS styling.
While the user proceed to the end of the wizard some inner working are performed form the plugin beside the simple page change and business rule enforcing.
When a page is displayed, the container (form) is decorated with a class called after the currentPageClassPrefix property. Given the property default value ("wizard-current") you will have the container decorated with a class called wizard-current-<index of the current page>.
The pages are indexed starting from zero. There are two extra marks, wizard-current-last and wizard-current-first used when the user is on the last and first page respectively.
In this example you will see the control buttons appear on appropriate pages (eg. the previous button is hidden in the first page). The labels on the left leverage on the same mechanism to show the current page.
Press this button to see it at work:
And peruse the css used to style the wizard to better comprehend what I mean.