jQuery Grid Plugin - jqGrid

hello, I want use the button "search" in the navigation bar but nothing work. I use "getpostdata' to see what is post.

bellow, it's my programm.

<?php

include($_SERVER['DOCUMENT_ROOT']."/paiement/include/dbconfig.php");
include($_SERVER['DOCUMENT_ROOT']."/paiement/include/JSON.php");

$json = new Services_JSON();

$page = $_GET['page']; // get the GETed page

$limit = $_GET['rows'];$sidx = $_GET['sidx'];
$sidx = $_GET['sidx'];
$sord = $_GET['sord'];
if(!$sidx) $sidx =1;

$wh ="";
$where_recherche = "";
$where_recherche_count = "";

if(isset($_REQUEST['searchField'])){
    $field = $_REQUEST['searchField'];
    switch ($field) {
    case "num_inform":
        $field = "fofacent.".$field;
        break;
    case "nom_banque":
        $field  = "fobanque.".$field;
        break;
    default:
        $field = "";
        break;   
    }       
}   
else {
    $field = "fofacent.num_inform";
}

if (isset($_REQUEST['searchString'])) {
    $value = $_REQUEST['searchString'];
}
else {
    $value = "1665";
}

if (isset($_REQUEST['searchOper'])) {
    $oper = $_REQUEST['searchOper'];
    switch ($oper) {
        case "eq":
            if(is_numeric($value)) {
                $wh = " = ".$value;
            } else {
                $wh = " = '".$value."'";
            }
            break;
        case "ne":
            if(is_numeric($value)) {
                $wh = " <> ".$value;
            } else {
                $wh = " <> '".$value."'";
            }
            break;
        case "lt":
            if(is_numeric($value)) {
                $wh = " < ".$value;
            } else {
                $wh = " < '".$value."'";
            }
            break;
        case "le":
            if(is_numeric($value)) {
                $wh = " <= ".$value;
            } else {
                $wh = " <= '".$value."'";
            }
            break;
        case "gt":
            if(is_numeric($value)) {
                $wh = " > ".$value;
            } else {
                $wh = " > '".$value."'";
            }
            break;
        case "ge":
            if(is_numeric($value)) {
                $wh = " >= ".$value;
            } else {
                $wh = " >= '".$value."'";
            }
            break;
        case "bw":
            $wh = " LIKE '".$value."%'";
            break;
        case "ew":
            $wh = " LIKE '%".$value."'";
            break;
        case "cn":
            $wh = " LIKE '%".$value."%'";
            break;
        default :
            $wh = "";
            break;
    }
    $where_recherche = " AND ".$field.$wh;
    $where_recherche_count = $field.$wh;
}
else {
    $oper = " = ";
    $wh = $oper.$value;
    $where_recherche = " AND ".$field.$wh;
    $where_recherche_count = $field." ".$oper." '".$value."'";
}

// Connection vers la base de données
$db = mysql_connect($dbhost, $dbuser, $dbpassword)
or die("Connection Error: " . mysql_error());

mysql_select_db($database) or die("Error conecting to db.");
        $result = mysql_query("SELECT COUNT(*) AS count FROM fofacent WHERE ".$where_recherche_count);
        $row = mysql_fetch_array($result,MYSQL_ASSOC);
        $count = $row['count'];       

        if( $count >0 ) {
            $total_pages = ceil($count/$limit);
        } else {
            $total_pages = 0;
        }       
        if ($page > $total_pages) $page=$total_pages;
        $start = $limit*$page - $limit; // Ne pas mettre $limit*($page - 1)
        if ($start<0) $start = 0;
        $SQL = "SELECT fofacent.cod_typfac, fofacent.cod_etafac, fofacent.dat_annee, fofacent.cod_banque, fobanque.nom_banque, fofacent.cod_fourni, fofacent.nom_foureg, fotypfac.cod_sens, fofacent.mnt_reg, fournis.cod_devise,fofacent.dat_echean, fofacent.num_facfou, fofacent.num_inform, fofacent.num_factur, fofacent.cod_etat FROM fofacent, fobanque, fotypfac, fournis WHERE (fobanque.cod_banque = fofacent.cod_banque AND fotypfac.cod_typfac = fofacent.cod_typfac AND FOURNIS.COD_ETAFOU = FOFACENT.COD_ETAFOU AND FOURNIS.COD_FOURNI = FOFACENT.COD_FOURNI ".$where_recherche.") ORDER BY ".$sidx." ".$sord. " LIMIT ".$start." , ".$limit;   
    
        $result = mysql_query( $SQL ) or die("Could not execute query.".mysql_error());
       
        $responce->page = $page;
        $responce->total = $total_pages;
        $responce->records = $count;
        $i=0;
        while($row = mysql_fetch_array($result,MYSQL_ASSOC)) {
            $responce->rows[$i]['id']=array($row['num_factur'].'-'.$row['cod_etafac'].'-'.$row['cod_typfac'].'-'.$row['dat_annee']); //Définition de la clé de l'enregistrement réccupéré       
            $responce->rows[$i]['cell']=array($row['cod_banque'],$row['nom_banque'],$row['cod_fourni'],$row['nom_foureg'],$row['cod_sens'],$row['mnt_reg'],$row['cod_devise'],$row['dat_echean'],$row['num_facfou'],$row['num_inform']);
            $i++;
        }
        echo $json->encode($responce);//envoie des informations du GRID
mysql_close($db);
?>

I don't uderstand how can I do my search. nothing work.

If you have an idea?!!

thank you for your help?!

Regards