var flecha = new Image(16, 14);
flecha.src = "inc/images/up.gif";

// mostrar y ocultar objetos en la paginas
function mostrar(imgObj, menuId){
	if (imgObj.alt == "Expandir")
	{
		imgObj.alt = "Contraer";
		document.documentElement.scrollTop = imgObj.offsetTop;
		imgObj.title = "Contraer";
		imgObj.src = flecha.src;
		getObj(menuId).className = "visible";
		
	}
	else
	{
		imgObj.alt = "Expandir";
		imgObj.title = "Expandir";
		imgObj.src = "inc/images/down.gif";
		getObj(menuId).className = "oculto";
	}
}

function getObj(refId)
{
	return document.getElementById(refId);
}