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;
	} 
}