gtk-assistant-set-forward-page-func (assistant func)

assistant -- a gtk-assistant widget
func -- a gtk-assistant-page-func page forwarding callback function, or nil to use the default one

Sets the page forwarding function to be func. This function will be used to determine what will be the next page when the user presses the Forward button. Setting func to nil will make the assistant to use the default forward function, which just goes to the next visible page.