Extjs中TextField中显示图标

{
                    width:500,
                    height : 25,
                    fieldLabel : ‘过滤条件‘,
                    itemId : ‘queryText‘,
                    labelAlign : ‘right‘,
                    allowBlank:true,
                    maxLength:10,
                    fieldStyle:{
                        background: ‘#fff url(../css/icons/zoom.png) no-repeat 5px center ‘, 
                        paddingLeft: ‘25px‘,
                    },
                    emptyText:‘人员编号/身份证号码/姓名‘,
                },