ExtJS -=- Combo with SimpleStore

{
     xtype: 'combo',
     fieldLabel: "Type Of Alert",
     store: new Ext.data.SimpleStore({
           fields: ['type', 'I18n'],
           data : [
                 ["POACK", "Purchase Order Ack"]
           ]
     }),

     valueField: 'type',
     displayField:'I18n',
     typeAhead: true,
     mode: 'local',
     forceSelection: true,
     triggerAction: 'all',

     selectOnFocus:true
}