function show_errors(xml) {
	/* clear old errors */
	var err, i, fe = $$('div.form_error');
	for (i = 0; i < fe.length; i++)
		fe[i].remove();

	err = xml.getElementsByTagName('form_errors');

	/* are there any form errors? */
	if (err.length == 0)
		return;
	else
		err = err[0].childNodes;

	var form = $('form');
	
	/* insert error messages */
	for (var i = 0; i < err.length; i++) {
		var div = document.createElement('div');
		div.appendChild(document.createTextNode(err[i].firstChild.nodeValue));
		div.className='form_error'; 
		form.select('span[name="' + err[i].tagName + '"]')[0].parentNode.appendChild(div);
	}
}