easyui combobox默认选中第一个

$('#cabinettype_add').combobox({
url:'${pageContext.request.contextPath}/cabinetTypeAction!getCabinetType.action?controltype='+CType,
valueField: 'cabinettypeid',
textField: 'cabinettypename',
editable:false,
panelHeight:'auto',
onLoadSuccess: function () {  //加载完成后,设置选中第一项
var val = $(this).combobox("getData");
for (var item in val[0]) {
if (item == "cabinettypeid") {
$(this).combobox("select", val[0][item]);
}
}
}

});