$oddrow = true;
while ($row = @mysql_fetch_assoc($query)) {
	echo '
<tr>';
	if($oddrow === true) {
		$cl = "row1"; $oddrow = false;
	} else {
		$cl = "row2"; $oddrow = true;
	}
	foreach ($row as $key=>$value) {
		echo '
	<td class="' . $cl . '">' . $value . '</td>';
	}
  	echo '
</tr>';
}