hey guys recenlty i made a script to move objects and save the orders

now i have a little to do to finish this script

everything works fine , just one question :

how can i save not numeric data in my json script

this is my script :

function updateWidgetData(){
    var items=[];

    $('.widget-title').each(function(){
        var weightId=$(this).attr('id');    

    $('.column').each(function(){
        var columnId=$(this).attr('id');

    $('.widget', this).each(function(i){

            var collapsed=0;
            if($(this).find('.widget-inside').css('display')=="none")
                collapsed=1;



            //Create Item object for current panel
            var item={
                id: $(this).attr('id'),
                collapsed: collapsed,
                order : i,
                column: columnId,
                weight: weightId
            };
            //Push item object into items array
            items.push(item);
        });
    });

    });
    //Assign items array to sortorder JSON variable
    var sortorder={ items: items };

    //Pass sortorder variable to server using ajax to save state
    $.post('updatePanels.php', 'data='+$.toJSON(sortorder), function(response){
        if(response=="success")
            $("#console").html('<div class="success">Saved</div>').hide().fadeIn(1000);
        setTimeout(function(){
            $('#console').fadeOut(1000);
        }, 2000);
    });
}

and this is my php script :

$data=json_decode($_POST["data"]);

foreach($data->items as $item)
{
    //Extract column number for panel
    $col_id=preg_replace('/[^\d\s]/', '', $item->column);
    //Extract id of the panel
    $widget_id=preg_replace('/[^\d\s]/', '', $item->id);
    $sql="UPDATE widgets SET column_id='$col_id', sort_no='".$item->order."', collapsed='".$item->collapsed."' WHERE id='".$widget_id."'";
    mysql_query($sql) or die('Error updating widget DB');
}
echo "success";

everything works fine till i use numeric value for columns' id but i need non numeric values forexample

 id='columnr'

i want to extract r

but i cant get it right

any help plz !?