var state;

function showhide(layer_ref) {
	if (document.all) { //IS IE
		if( eval( "document.all." + layer_ref ) )
			state = eval("document.all." + layer_ref + ".style.display");
	}
	if (document.layers) { //IS NETSCAPE 4 or below
		state = document.layers[layer_ref].display;
	}
	if (document.getElementById &&!document.all) {
		hza = document.getElementById(layer_ref);
		state = hza.style.display;
	}
	
	if (state == 'none') {
		state = 'block';
	} else {
		state = 'none';
	}

	if (document.all) { //IS IE
		if( eval( "document.all." + layer_ref ) )
			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;
	}
}