if(window.addEventListener){
  window.addEventListener("load", menuHome, true);
} else if (window.attachEvent){
	window.attachEvent("on"+"load", menuHome);
 
} 

function menuHome() {
  var oMenu = document.getElementById('navegacionhorizontal');
  var aLi = oMenu.getElementsByTagName('li');
  for (var i=0;i<aLi.length;++i) {
    aLi[i].onmouseover = desplegarSecundarios;
    aLi[i].onmouseout = ocultarSecundarios;
  }
}


function desplegarSecundarios() {
      this.className += " estilohover";
}


function ocultarSecundarios(){
      this.className = this.className.replace(" estilohover", "");
}