function display_options() {
	document.getElementById('position_span').style.display = 'none';
	document.getElementById('location_span').style.display = 'none';
	document.getElementById('area_span').style.display = 'none';
	document.getElementById('jurisdiction_span').style.display = 'none';
	if (document.form.by.value != 'all') {
		var by = document.form.by.value;
		document.getElementById(by+'_span').style.display = 'inline';
	}
}