Noob to OOP in PHP

I am trying to write a class for MySQL that just handles simple stuff. I can get most of it working, but I can't get the FetchRows() function in the class to return anything. Here is my

Query($query);
$numrows = $db->NumRows($result);

echo $numrows . ' record(s) returned from table.
';

while($row = $db->FetchRows($result)) {
	$row['last_name'] . '
';
}
$db->Flush($result);

$db->Close();

?>

any ideas?