var relative_path = '';

Event.observe(window, 'load', function() {
                var pattern, a, img_fr, img_en;
                    if ( this.location.pathname.startsWith(relative_path+ '/en/') ) {
                                pattern = new RegExp('^' + relative_path+ '/en/');
                                a = new Element('a', { href:this.location.pathname.sub(pattern, relative_path + '/') });
                                img_fr = new Element('img', { src:relative_path + '/images/fr_off.gif', alt: 'Français', border: '0' });
                                img_en = new Element('img', { src:relative_path + '/images/en.gif', alt: 'English', border: '0' });
                                a.insert(img_fr);
                                $('languages').insert(a);
                                $('languages').insert(img_en);
                        } else {
                                if ( relative_path.empty() )
                                        var href = relative_path + '/en' + this.location.pathname;
                                else {
                                        pattern = new RegExp('^' + relative_path);
                                        var href = this.location.pathname.sub(pattern, relative_path + '/en')
                                }
                                a = new Element('a', { href: href });
                                img_fr = new Element('img', { src:relative_path + '/images/fr.gif', alt: 'Français', border: '0' });
                                img_en = new Element('img', { src:relative_path + '/images/en_off.gif', alt: 'English', border: '0' });
                                a.insert(img_en);
                                $('languages').insert(img_fr);
                                $('languages').insert(a);
                        }
                });