Array per GD da con KEY e VALUE da Query

[Tuning]

ho trovato questo nuovo esempio che sto modificando

$x= mysql_query("SELECT xFROM ARL WHERE (x!='Null' and x!='File') order by ident  ASC");$x= mysql_fetch_object($x)->x;$y= mysql_query("SELECT y FROM ARL WHERE (x!='Null' and x!='File') order by ident  ASC");$y= mysql_fetch_object($y)->y;
$data[$y] = $x;
$graph->addData($data);
$graph->setTitle($titolo);
$graph->setBars(false);
$graph->setLine(true);
$graph->setDataPoints(true);
$graph->setDataPointColor(‘blue’);
$graph->setDataValues(true);
$graph->setDataValueColor(‘green’);
$graph->createGraph(); 

ma mi restituisce questo
Fatal error: Call to a member function addData() on a non-object in graph_index.php on line 30

aiuto!