i have tried display header column from database used ext.XTemplate, but when i have a store and i want to mapping data store into ext.XTemplate displaying error onMetachange is undifined..

this is my code
Code:
function search() {
        var params = params || {};
        recForm = this.getForm();
            params = this.getForm().getValues();
            Ext.Ajax.request({
                url: baseHref + newhid.fluid_consumption_analysis.controller + '/get_header',
                method : 'POST',
                params : params,
                success : function(response) {
                    var resp = Ext.decode(response.responseText);
                    if (resp) {
                    countTab = resp.length;
                    var mainPanel = Ext.getCmp('fluid_panel');
                        var items1 = mainPanel.items.get(1);
                        //--destroy items if exists
                        if (items1) {
                            mainPanel.remove(items1, true);
                            mainPanel.doLayout();    
                        }
                    var comp_mod = "";
                    var comp_mod2 = "";
                    //var newStore = newhid.fluid_consumption_analysis.store();
                    for (i=0;i<countTab;i++) {
                    
                        var colHeader = new Array();
                        colCount = resp[i].colHeader.length;
                        
                    
                        var recTpl1 = "";
                        var recTpl2 = "";
                        
                        //-- define th, new field of store and template
                        for(c=0;c<colCount;c++) {
                            comp_mod += '<th width="150" colspan="3">'+resp[i].colHeader[c].header+'</th>';
                            comp_mod2 += '<th width ="50">Cum Usage</th><th>Fluid Rate</th><th>Cycle</th>';
                            
                        }
                        //-- create XTemplate
                        var html = new Ext.XTemplate('',
                            '<div style="overflow:auto"><table bordercolor="#000000" border="1">'
                            ,'<thead align="center">'
                            ,'<tr>'
                            ,'<th width="80" rowspan="2">Eq No</th>'
                        
                            ,comp_mod
                            ,'</tr>'
                            ,'<tr>'
                            ,comp_mod2
                            ,'</tr>'
                            
                            ,'</tr></thead><tbody>'
                            ,'<tpl for=".">'
                            ,'<tr align="center">'    
                             ,'<td>{eqplan}</td>'
                            ,'</tr>' 
                            ,'</tpl>'
                            ,'</tbody></table></div>');
                        //--create new dataview
                         var dataView = new Ext.DataView({
                            store : newhid.fluid_consumption_analysis.store(),
                            tpl: html,
                            overClass: 'x-view-over',
                            itemSelector: 'div.thumb-wrap'
                         });
                        mainPanel.add(html); 
                        mainPanel.render();        
                        mainPanel.doLayout(true);
                    }  
                    } 
                },
                failure : function(response) {
                    var errorMsg = response.responseText;
                    Ext.Msg.alert('Failure', errorMsg);
                }
            });        
        
    }

and this my store
Code:
newhid.fluid_consumption_analysis.store = Ext.extend(Ext.data.JsonStore, {
    constructor: function (config) {
        config = config || {};
        config.url = config.url || (baseHref + newhid.fluid_consumption_analysis.controller + '/getData');
        config.root = config.root || 'rows';
        config.autoDestroy = config.autoDestroy || true;
        config.autoLoad = false;
        config.storeAutoLoad = false;        
        config.fields = [ 
        {name : 'eqplan',mapping:'eqplan'}
        ];
        newhid.fluid_consumption_analysis.store.superclass.constructor.call(this, config);
    }
});
thanks