var state = new Array();

function showhide(layer_ref) {

	
	if(!(layer_ref in state))
	{
		state[layer_ref] = 'none';
	}	
	if (state[layer_ref] == 'block') {
		state[layer_ref] = 'none';
	} else {
		state[layer_ref] = 'block';
	}
	sync_display(layer_ref);
}

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