Flex 4 -> Datagrid add checkbox to a column

Hello all.

I am trying to add a checkbox to a datagrid column, so that i can use it to delete a record from the array.  My datagrid is as follows

    <mx:DataGrid x="10" y="40" width="903" dataProvider="{questionsArr}" sortableColumns="false" draggableColumns="false" editable="true">
        <mx:columns>
            <mx:DataGridColumn headerText="No." dataField="Number" width="100" editable="false"/>
            <mx:DataGridColumn headerText="Question" dataField="Question" />
            <mx:DataGridColumn headerText="Delete"  width="100" />
        </mx:columns>
    </mx:DataGrid>

The user inputs questions into the array via a textinput box.

But what i want to do is add a checkbox to the "Delete" column.  If anyone could help me with this that would be great !