function TR_alternate(sTable_id, sClassname, bEven_rows)
{ 
	var row, r = 0, table = document.getElementById(sTable_id);
	var offset = (bEven_rows) ? 0 : 1;
	while (row = table.rows.item(r++))
		if ((r + offset) % 2 != 0 && row.parentNode.nodeName.toUpperCase() != 'THEAD')
			row.className = sClassname;
}