function pf_toggle()
{
	var v = document.getElementById('pf_container');
	var show = v.style.display == 'none';

	v.style.display = show ? '' : 'none';

	var p = '_on', r = '_off';
	if (show) { var t = p; p = r; r = t; }

	var d = document.getElementById('pf_mark').getElementsByTagName('div')[0];
	d.className = d.className.replace(p, r);
}