var state = 'none';

function showhide(layer_ref)
{
	if(state == 'block')
	{
		state = 'none';
	}
	else
	{
		state = 'block';
	}

	if(document.all)
	{ //IS IE 4 or 5 (or 6 beta)
		eval("document.all." +layer_ref+ ".style.display = state");
	}
	
	if (document.layers) 
	{ //IS NETSCAPE 4 or below
		document.layers[layer_ref].display = state;
	}

	if (document.getElementById &&!document.all) 
	{
		hza = document.getElementById(layer_ref);
		hza.style.display = state;
	}
}