在jqgrid中设置我自己的列名

我想在jqgrid中添加我自己的列名，而且我想防止jqgrid根据sql查询自动添加的列名。

我使用这段代码来做到这一点，但它也得到列的名称，我没有在方法$grid->setColModel(null, null, $mylabels);

有没有人能告诉我应该写什么代码来删除jqgrid中额外添加的列。

require_once '/var/www/html/zbajtmp/public/jqgrid/jq-config.php';
// include the jqGrid Class
require_once "/var/www/html/zbajtmp/public/jqgrid/php/jqGrid.php";
// include the driver class
require_once "/var/www/html/zbajtmp/public/jqgrid/php/jqGridPdo.php";
// Connection to the server
$conn = new PDO(DB_DSN,DB_USER,DB_PASSWORD);
// Tell the db that we use utf-8
$conn->query("SET NAMES utf8");
// Create the jqGrid instance
$grid = new jqGridRender($conn);
 // Write the SQL Query
//$grid->SelectCommand = 'SELECT OrderID, OrderDate, CustomerID, Freight, ShipName  FROM orders';
$grid->SelectCommand = 'SELECT *  FROM clinic';
// set the ouput format to json
$grid->dataType = 'json';
// Let the grid create the model
//$grid->setColModel();
$mylabels = array(
"clinic_name"=>"Clinic ame",
"clinic_address"=>"Address",
"HomePhone"=>"Home Phone",
"WorkPhone"=>"Work Phone",
"Email_Id"=>"Email",
);
// Let the grid create the model with the desired labels
$grid->setColModel(null, null, $mylabels);
// Set the url from where we obtain the data
//$grid->setUrl('/var/www/html/zbajtmp/application/views/scripts/clinic/grid.php');
$grid->setUrl('http://sunlinux/zbajtmp/application/views/scripts/clinic/grid.php');
// Set grid caption using the option caption
$grid->setGridOptions(array(
    "caption"=>"This is my custom Caption...",
    "rowNum"=>50,
    "sortname"=>"id",
    "hoverrows"=>true,
    "rowList"=>array(20,50,100,1000),
    "width"=>"100%",
    "height"=>350,
"footerrow"=>true,
"rownumbers"=>true,
"multiselect"=>true,
"altRows"=>true,
"altclass"=>'clsalt',
"loadtext"=>"<div class='loadingbox'>Please wait. Loading...</div>",
    ));

$grid->renderGrid('#grid','#pager',true, null, null, true,true);

$conn = null;