Problem with dhtmlxconnector

Je suis tout débutant en dhtmx, j’ai écrit un petit code en utilisant le composant
dhtmlxconnector, mais jusqu’a present je ne parviens pas à charger les données de mes tables dans une grille, pourtant j’ai respecté ce qui est dans la documentation.
Here is my client side code.

<html>
	<head>
		<title>
			premier test langage pljava
		</title>
		<style>
			.global
			{
				width:400px;
				height:400px;
				margin:auto;
			}
		</style>
		<script src="codebase/dhtmlx.js" type="text/javascript"></script>
		<script src="codebase/connector.js"></script>
		<script src="codebase/dataprocessor.js"></script>
		<link rel="STYLESHEET" type="text/css" href="codebase/dhtmlx.css">
		<script type="text/javascript">  
			var mygrid,myDP;
			function doOnLoad()
			{
				mygrid = new dhtmlXGridObject('gridbox');
				mygrid.setImagePath("codebase/imgs/");
				mygrid.setHeader("nom,prenom,email,telephone,ville,filliere,id_classe");
				mygrid.attachHeader("#connector_text_filter,#connector_select_filter,#connector_select_filter");
				mygrid.setInitWidths("200,80,*");
				mygrid.setColTypes("ro,ed,ed");
				mygrid.setColSorting("str,connector,str");
				mygrid.init();
					mygrid.load("traitement.php");
			 
				myDP = new dataProcessor("traitement.php");
					myDP.init(mygrid);		 
			}
		</script>		
	</head>
	<body onload="doOnLoad()">
		<div id="gridbox" style="width:450px;height:250px;border:1px solid #A4BED4;"></div>
	</body>
</html>

the server side code

<?php
try {		
		require_once("codebase/grid_connector.php");
		$res=new PDO('pgsql:host=localhost port=5436 dbname=etudiant', 'postgres', 'fb12fb12b');
		$gridConn=new GridConnector($res,"PDO");
if ($gridConn->is_select_mode())
		{
			$gridConn->render_sql("SELECT * FROM etudiant,classe WHERE etudiant.id_classe=classe.id_classe","etudiant.id_etudiant","nom,prenom,email,telephone");
		}else
		{
			 $gridConn->render_table("etudiant","id_etudiant","nom,prenom,email,telephone");
		}
		//$sql=$db->query("SELECT * FROM resultatresultset_test()");
		
		//$result = $sql->fetchAll();
          //var_dump($result);
    }
	catch (PDOException $e)
	{
		print "Erreur !: " . $e->getMessage() . "<br/>";
		die();
    }

	?>

i have following error:

[15-Jan-2013 07:29:22] PHP Warning:  PDO::__construct() expects parameter 1 to be string, object given in H:\Program Files\Zend\Apache2\htdocs\testpljava\codebase\base_connector.php on line 344
[15-Jan-2013 07:29:22] PHP Fatal error:  Call to a member function select() on a non-object in H:\Program Files\Zend\Apache2\htdocs\testpljava\codebase\base_connector.php on line 513

quelqu’un peut il m’aider svp

You need to include one more php file

require_once("codebase/grid_connector.php"); require("codebase/db_pdo.php"); //this one is missed

Thank you for your availability,
the current problem is that instead of seeing the displayed grid, I rather a xml with here.

<rows><row id="8"><cell>NGAMI</cell><cell>Abraham</cell><cell>n.abraham@axxentis.com</cell><cell>94269442</cell><cell>CCNP pro</cell><cell>MElong</cell></row><row id="1"><cell>FOUAPE</cell><cell>Bruno</cell><cell>bruno.fouape@axxentis.com</cell><cell>94269442</cell><cell>GLT</cell><cell>Yaoundé</cell></row><row id="9"><cell>Beyala</cell><cell>DCM</cell><cell>b.d.g@axxentis.com</cell><cell>98653212</cell><cell>ITIL_v3</cell><cell>Douala</cell></row><row id="5"><cell>NOUMBI</cell><cell>Josiane</cell><cell>j.noumbi@axxentis.com</cell><cell>335269355</cell><cell>CCNP</cell><cell>DAKAR</cell></row><row id="7"><cell>TEFOM</cell><cell>Achile</cell><cell>tefom.achile@axxentis.com</cell><cell>22356923</cell><cell>ITIL v3</cell><cell>Bafoussam</cell></row><row id="6"><cell>FEZE</cell><cell>Cedric</cell><cell>feze@axxentis.com</cell><cell>7452639842</cell><cell>SIG</cell><cell>DOUAL</cell></row><row id="4"><cell>TSAGUE</cell><cell>GEOVANI</cell><cell>tsague@axxentis.com</cell><cell>78541236</cell><cell>OCP</cell><cell>Douala</cell></row></rows>

with the following message:

Any style information associated with it does not seem XML file. The document tree is shown below.

The data looks valid.
When loading php feed file you will see the xml data only, but if you load html file with js code and grid.load command - it must show correct grid with data

Stanislav,
thank you very much for your availability.