function horizontal() {
 
   var navItems = document.getElementById("menu_dropdown").getElementsByTagName("li");
    
   for (var i=0; i< navItems.length; i++) {
      if(navItems[i].className == "submenu") {
		 navItems[i].onmouseover=function() {this.style.backgroundImage = "url('http://www.portoseguro.com.br/lib/imagens/menu/bg_menu_drop.jpg')";}
   		 navItems[i].onmouseout=function() {this.style.backgroundImage = "url('')";this.style.backgroundColor = "#064a6a";}
		 
         if(navItems[i].getElementsByTagName('ul')[0] != null) {
            navItems[i].onmouseover=function() {this.getElementsByTagName('ul')[0].style.display="block";this.style.backgroundImage = "url('http://www.portoseguro.com.br/lib/imagens/menu/bg_menu_drop.jpg')";}
            navItems[i].onmouseout=function() {this.getElementsByTagName('ul')[0].style.display="none";this.style.backgroundImage = "url('')";this.style.backgroundColor = "#064a6a";}
         }
      }
   }
 
}