How to use salesforce PageReference to redirect after a new record insert?

I found an answer here that might work for you, where the solution would be to change your "Save" method to the following:

Public salesforce PageReference saveAndRedirect() { if(controller.save() != null) { PageReference redirectPage = Page.force_OrderDetail; redirectPage.setRedirect(true); redirectPage.getParameters().put('id',controller.getId()); return redirectPage; } return null; }
Then change your action on the VF page to "saveAndRedirect".
Reason:
1) Your "save" function is shadowed by the standard controller's "save" function, so your code won't work. You have to rename the function, and call that action instead.