function submenu(id) {
		var arrSubmenu = new Array("corredor_humedales", "sistema_paraguay_parana", "educacion_humedales", "seminarios_internacionales");
		var mySubmenu = document.getElementById(id);
		var mySubmenuItem = document.getElementById("submenu_item_"+id);
		
		for (i=0;i<arrSubmenu.length;i++) {
			document.getElementById(arrSubmenu[i]).style["display"] = "none";
			document.getElementById("submenu_item_" + arrSubmenu[i]).style["backgroundImage"] = "url(none)";
		}
		
		mySubmenu.style["display"] = "block";		
		mySubmenuItem.style["backgroundImage"] = "url(images/seccion/submenu_item_bg.gif)";
	}