I am trying to add paging for my list in js.Its showing no of pages correctly in bbar as per the given pagesize limit.But its not filtering and it listing all data in the 1st page itself.If any one know please help me.

This is my js code:

Code:
Ext.onReady(function(){
    var store = new Ext.data.GroupingStore({
        id:'store',
        url:'../crm/get_totaldb_list.jsp',
        autoLoad:true,
          reader:new Ext.data.ArrayReader({},[
           {name:'cusname'},
            {name:'mobileno'},
            {name:'cmpname'},
            {name:'location'},
            {name:'status'},
            {name:'camp_name'}, ])
    });
var pagesize =5;
var paging_toolbar = new Ext.PagingToolbar({
             pageSize: pagesize,
             displayInfo: true,
             emptyMsg: 'No data found',
             store: store
});
    var grid = new Ext.grid.GridPanel({
        width:550,
        height:370,
         id:grid,
         renderTo:'CtlDBList',
        trackMouseOver:false,
        disableSelection:true,
        loadMask: true,
       columns:[new Ext.grid.RowNumberer(),
           {
            id: 'topic', 
            header: "Name",
            dataIndex: 'cusname',
            width: 200,
            sortable: true
        },{
            header: "Mobile No",
            dataIndex: 'mobileno',
            width:'',
            align: 'right',
            sortable: true
        },{
            header: "Company Name",
            dataIndex: 'cmpname',
            width:'',
            align: 'right',
            sortable: true
        },{
            header: "Location",
            dataIndex: 'location',
            width:'',
            align: 'right',
            sortable: true
        },{
            header: "Status",
            dataIndex: 'status',
            hidden:true,
            width:'',
            align: 'right',
            sortable: true
        }],
       store:store,
       bbar:paging_toolbar
    })
    grid.render('topic-grid');
    store.load({params:{start:0,limit:pagesize}});
});