Default sorting the Dojo DataGrid

This is how I have configure default sorting for our grids:

dojo.declare("DefaultSortableGrid", dojox.grid.DataGrid, {
    sortInfo: 1 // the index (1-based) of the column 
                // to sort, + => asc, - => desc
});

And then I use DefaultSortableGrid when defining the grid:

<div dojoType="DefaultSortableGrid"
    id="grid"
    rowsPerPage="50">
</div>

Pretty simple really.