function alternateRowColors ()
{
	tables = document.getElementsByTagName ('table');
	for (x = 0; x < tables.length; x++)
	{
		if (tbody = tables[x].getElementsByTagName ('tbody')) rows = tbody[0].getElementsByTagName ('tr');
		else rows = tables[x].getElementsByTagName ('tr');

		for (i = 0; i < rows.length; i++)
		{
			if (i%2) rows[i].setAttribute ('class', rows[i].getAttribute ('class') + ' even');
			else rows[i].setAttribute ('class', rows[i].getAttribute ('class') + ' odd');
		}
	}
}