	<!--
	// toggle visibility
	function blocking(nr)
	{
		if (document.layers)
		{
			current = (document.layers[nr].display == 'none') ? 'block' : 'none';
			document.layers[nr].display = current;
		}
		else if (document.all)
		{
			current = (document.all[nr].style.display == 'none') ? 'block' : 'none';
			document.all[nr].style.display = current;
		}
		else if (document.getElementById)
		{
			vista = (document.getElementById(nr).style.display == 'none') ? 'block' : 'none';
			document.getElementById(nr).style.display = vista;
		}
	}
	-->