function toggle(id){	if (document.layers)	{		current = (document.layers[id].display == 'none') ? 'block' : 'none';		document.layers[id].display = current;	}	else if (document.all)	{		current = (document.all[id].style.display == 'none') ? 'block' : 'none';		document.all[id].style.display = current;	}	else if (document.getElementById)	{		vista = (document.getElementById(id).style.display == 'none') ? 'block' : 'none';		document.getElementById(id).style.display = vista;	}}