jQuery Grid Plugin - jqGrid

Hello, im just starting using jQuery plugin, and i think im starting with the wrong foot  =S

I have done the example from the wiki page, using jQGrid, and I've done everything it says i have to do, but no record is shown on the grid ones i execute the code.

Im using jqgrid 1.4.2 en the code of the PHP (where i thing the problem is):

<?php

//include the information needed for the connection to MySQL data base server.

// we store here username, database and password

include("connections/dbconfig.php");

// to the url parameter are added 4 parameters as described in colModel

// we should get these parameters to construct the needed query

// Since we specify in the options of the grid that we will use a GET method

// we should use the appropriate command to obtain the parameters.

// In our case this is $_GET. If we specify that we want to use post

// we should use $_POST. Maybe the better way is to use $_REQUEST, which

// contain both the GET and POST variables. For more information refer to php documentation.

// Get the requested page. By default grid sets this to 1.

$page = $_GET['page'];

// get how many rows we want to have into the grid - rowNum parameter in the grid

$limit = $_GET['rows'];

// get index row - i.e. user click to sort. At first time sortname parameter -

// after that the index from colModel

$sidx = $_GET['sidx'];

// sorting order - at first time sortorder

$sord = $_GET['sord'];

// if we not pass at first time index use the first column for the index or what you want

if(!$sidx) $sidx =1;

// connect to the MySQL database server

$db = mysql_connect($dbhost, $dbuser, $dbpassword) or die("Connection Error: " . mysql_error());

// select the database

mysql_select_db($database) or die("Error connecting to db.");

// calculate the number of rows for the query. We need this for paging the result

$result = mysql_query("SELECT COUNT(*) AS count FROM invheader");

$row = mysql_fetch_array($result,MYSQL_ASSOC);

$count = $row['count'];

// calculate the total pages for the query

if( $count > 0 && $limit > 0) {

$total_pages = ceil($count/$limit);

} else {

$total_pages = 0;

}

// if for some reasons the requested page is greater than the total

// set the requested page to total page

if ($page > $total_pages) $page=$total_pages;

// calculate the starting position of the rows

$start = $limit*$page - $limit;

// if for some reasons start position is negative set it to 0

// typical case is that the user type 0 for the requested page

if($start <0) $start = 0;

// the actual query for the grid data

$SQL = "SELECT invid, invdate, amount, tax,total, note FROM invheader ORDER BY $sidx $sord LIMIT $start , $limit";

$result = mysql_query( $SQL ) or die("Couldn't execute query.".mysql_error());

// we should set the appropriate header information. Do not forget this.

header("Content-type: text/xml;charset=utf-8");

$s = "<?xml version='1.0' encoding='utf-8'?>";

$s .= "<rows>";

$s .= "<page>".$page."</page>";

$s .= "<total>".$total_pages."</total>";

$s .= "<records>".$count."</records>";

// be sure to put text data in CDATA

while($row = mysql_fetch_array($result,MYSQL_ASSOC)) {

$s .= "<row id='". $row[invid]."'>";

$s .= "<cell>". $row[invid]."</cell>";

$s .= "<cell>". $row[invdate]."</cell>";

$s .= "<cell>". $row[amount]."</cell>";

$s .= "<cell>". $row[tax]."</cell>";

$s .= "<cell>". $row[total]."</cell>";

$s .= "<cell><![CDATA[". $row[note]."]]></cell>";

$s .= "</row>";

}

$s .= "</rows>";

echo $s;

?>

Thanks.