bilingual menus. Canadian way

Hi Canadian Guys and Girls

How to display the switch language bar in the main menu like you do on your sites (government and community alike and switch between Fr/En without showing the other menu? I would like to do a site following the Canadian way (language switcher in the center menu and when you click one language you go the respective side). I'm using D6 with Internationalization/Localization/Nices menues modules

I work on local server, have all pages in 2 languages : en/es, but menu tabs in both languages appear in the menu central bar, can you help me with this?