function showhide(layer_ref) {

	if (document.all) { //IS IE 4 or 5 (or 6 beta)
		currentstate = document.all[layer_ref].style.display;
		if (currentstate == 'block') {
			document.all[layer_ref].style.display = 'none';
		} else {
			document.all[layer_ref].style.display = 'block';
		}
	}
	
	if (document.layers) { //IS NETSCAPE 4 or below
		currentstate = document.layers[layer_ref].display;
		if (currentstate == 'block') {
			document.layers[layer_ref].display = 'none';
		} else {
			document.layers[layer_ref].display = 'block';
		}
	}
	
	if (document.getElementById &&!document.all) {
		hza = document.getElementById(layer_ref);
		currentstate = hza.style.display;
		if (currentstate == 'block') {
			hza.style.display = 'none';
		} else {
			hza.style.display = 'block';
		}
	}
}