if (!Ext.grid.GridView.prototype.templates) {    
    Ext.grid.GridView.prototype.templates = {};    
}    
Ext.grid.GridView.prototype.templates.cell = new Ext.Template(    
    '<td class="x-grid3-col x-grid3-cell x-grid3-td-{id} x-selectable {css}" style="{style}" tabIndex="0" {cellAttr}>',    
    '<div class="x-grid3-cell-inner x-grid3-col-{id}" {attr}>{value}</div>',    
    '</td>'   
);  