jQuery Grid Plugin - jqGrid

I have an inline editing grid with a json back end.  That all works fine.  However, if a cell is changed via setCell a call to saveRow does not trigger a call to the editurl.  The cell changes in the grid, but the change does not get saved back to the server.  Is there a way to force a row save to the server?

function onMoveRowDown(eventObject)
{
    var sr = jQuery("#pt_grid").getGridParam("selrow");
    if( sr != null )
    {       
        var order = jQuery("#pt_grid").getCell(sr,'order');
        order = parseInt(order) + 1;
        jQuery("#pt_grid").setCell(sr,'order',order);    
        jQuery("#pt_grid").saveRow(sr, successfunc=saveRowSuccess, url=null, extraparam = {'order': order});      
    }
    else
    {
        alert("Please Select Row");
    }
       
}

Thanks!

Andy