jQuery Grid Plugin - jqGrid

Hello,

It's very important. I don't understand why buttons "add", "delete" "search"  don't work.

If I don't find the solution, I will have big problem with my boss. please help me!!! below, it's my cod:

<script type="text/javascript">
// syntaxe pour creer le GRID
jQuery(document).ready(function(){
    var lastsel;
    jQuery("#client").jqGrid({
           url:'/paiement/traitement/server.php?nd='+new Date().getTime(),
        datatype: "json",
           colNames:['Inv No','Date', 'Client', 'Amount','Tax','Total','Notes'],
           colModel:[
               {name:'invid',index:'invid', width:55,sorttype:"int"},
               {name:'invdate',index:'invdate', width:90,editable:true,sorttype:"date",formatter:'date',formatoptions:{newformat: 'd/m/Y'}},
               {name:'name',index:'name', width:100,editable:true,sorttype:"text"},
               {name:'amount',index:'amount', width:80, align:"right",sorttype:"float",editable:true,editrules:{number:true}},
               {name:'tax',index:'tax', width:80, align:"right",sorttype:"float",editable:true,editrules:{number:true}},
               {name:'total',index:'total', width:80,align:"right",sorttype:"float",editable:true,editrules:{number:true}},
               {name:'note',index:'note', width:150, sortable:false,editable:true}
           ],
           rowNum:10,
           rowList:[10,20,30],
           pager: jQuery('#pclient'),
           sortname: 'invid',
           imgpath: '/paiement/jqgrid/themes/coffee/images/',
        viewrecords: true,
        sortorder: "asc",
        caption: "tableau test",      
       
        onSelectRow: function(invid){
            if(invid && invid!==lastsel){               
                    var ret = jQuery("#client").getRowData(invid);               
                    jQuery('#client').restoreRow(lastsel);                    
                     //jQuery('#client').editRow(invid,true,pickdates,success,'/paiement/traitement/mise_a_jour_bd.php',{'invid':+ret.invid},aftersavefunc,onerrorfunc);
                     jQuery('#client').editRow(invid,true,pickdates,'','/paiement/traitement/mise_a_jour_bd.php',{'invid':+ret.invid},'',onerrorfunc);
                    lastsel=invid;
             }
        },
        editurl: "/paiement/traitement/server.php",
    }).navGrid('#pclient', {refresh:true,add:true,del:true,search:true,edit:false}
    );   

//with button out the nav bar

    $("#search").click(function(){
        jQuery("#client").searchGrid(
            {sopt:['cn','bw','eq','ne','lt','gt','ew']}
        );
    });
    $("#add").click(function(){
            jQuery("#client").editGridRow("new",{height:280,reloadAfterSubmit:false,addCaption: "Add Record"});
    });
    function pickdates(invid){
        jQuery("#"+invid+"_invdate","#client").datepicker({dateFormat:"dd/mm/yy"});
    }
    function onerrorfunc() {
        alert('La mise à jour de la base de données c\\'est mal passée!');     

    }
});

Please, help me. It's very important!!!!!!!!

thank you all!!

Aurore