<!-- Código para el Menú -->
/***********************************************
* Switch Menu script- by Martial B of http://getElementById.com/
* Modified by Dynamic Drive for format & NS4/IE4 compatibility
* Visit http://www.dynamicdrive.com/ for full source code
***********************************************/
function SwitchMenu(obj)
	{ if(document.getElementById)
		{
			var el = document.getElementById(obj);
			var ar = document.getElementById("masterdiv").getElementsByTagName("span"); //DynamicDrive.com change
			if(el.style.display != "block")
				{ //DynamicDrive.com change
				for (var i=0; i<ar.length; i++)
					{
						var clase=ar[i].className;  //Modificacion mia para que reconozca distintos tipos de submenu
						if (clase.substring(0,7)=="submenu") //DynamicDrive.com change
							ar[i].style.display = "none"; 
					}
				el.style.display = "block";
				} 
			else
				{ el.style.display = "none"; } 
		} 
	}
<!-- Fin Código Menú -->