I have an XML file with this data.

```
<resultSet> 
<MerchandiseAssortmentCategory>
                                <merchandiseAssortmentCategoryId>275</merchandiseAssortmentCategoryId>
                                <merchandiseAssortmentCategoryName>D21 Plywood</merchandiseAssortmentCategoryName>
                                <merchandiseSubordinateClasses>
                                                <merchandiseSubordinateClass>
                                                                <merchandiseSubordinateClassNumber>2</merchandiseSubordinateClassNumber>
                                                                <merchandiseSubordinateClassDescription>SHEATHING</merchandiseSubordinateClassDescription>
                                                </merchandiseSubordinateClass>
                                                <merchandiseSubordinateClass>
                                                                <merchandiseSubordinateClassNumber>3</merchandiseSubordinateClassNumber>
                                                                <merchandiseSubordinateClassDescription>WAFERBOARD</merchandiseSubordinateClassDescription>
                                                </merchandiseSubordinateClass>
                                                <merchandiseSubordinateClass>
                                                                <merchandiseSubordinateClassNumber>4</merchandiseSubordinateClassNumber>
                                                                <merchandiseSubordinateClassDescription>SANDED</merchandiseSubordinateClassDescription>
                                                </merchandiseSubordinateClass>
                                </merchandiseSubordinateClasses>
</MerchandiseAssortmentCategory>
</resultSet> 

```

I need to populate a data grid with the merchandiseAssortmentCategoryName and all its merchandiseSubordinateClassNumber(s) seperated with commas in the same row. 

the categoryList is which is the dataprovider for the dataGrid is defined as follows :

```
this.categoryList= evt.result.resultSet.MerchandiseAssortmentCategory;

```

and this is how the dataGrid is defined

```
<mx:DataGrid x="466" y="73" width="192" height="225" 
        dataProvider="{categoryList}" 
        verticalScrollPolicy="on" 
        id="categories"
        rowCount="10" enabled="true">
        <mx:columns>
            <mx:DataGridColumn headerText="Category name" dataField="merchandiseAssortmentCategoryName"/>
            <mx:DataGridColumn headerText="Subclasses" dataField="merchandiseSubordinateClasses.merchandiseSubordinateClass.merchandiseSubordinateClassNumber"/>

            </mx:columns>
    </mx:DataGrid>

```

When i run this, only the category name is filled. the subordinateclass number is just blank. Help out with this. Thanks