// Controle de la navigation au survol
function initJsNavigation(){
  //initThirdNavigation();
  var nav1 = document.getElementById("nav1");
  var lis = nav1.getElementsByTagName("li");
  for(var i=0; i<lis.length; i++){
    if(lis[i].className != "alternative"){
      lis[i].onmouseover = function(){
        hideJsNav2();
   
        var js_nav2 = document.getElementById('js_nav2_' + this.id);
        js_nav2.style.display = 'block';
      }
    }
  }  
}

function hideJsNav2(){
  var uls = document.getElementsByTagName("ul");
  for(var i=0; i<uls.length; i++){
    if(uls[i].className == 'js_nav2'){
      uls[i].style.display = 'none';
    }
  }
}