convert dataset into JSON

public static class myclassGeneral
{
    static object RowsToDictionary(this DataTable table)
    {

        var columns = table.Columns.Cast<DataColumn>().ToArray();

        return table.Rows.Cast<DataRow>().Select(r => columns.ToDictionary(c => c.ColumnName, c => r[c]));

    }

    static Dictionary<string, object> ToDictionary(this DataTable table)
    {

        return new Dictionary<string, object>

   {

       { table.TableName, table.RowsToDictionary() }

   };

    }

    static Dictionary<string, object> ToDictionary(this DataSet data)
    {

        return data.Tables.Cast<DataTable>().ToDictionary(t => t.TableName, t => t.RowsToDictionary());

    }

    public static string GetJSONString(DataTable table)
    {

        JavaScriptSerializer serializer = new JavaScriptSerializer();

        return serializer.Serialize(table.ToDictionary());

    }

    public static string GetJSONString(DataSet data)
    {

        JavaScriptSerializer serializer = new JavaScriptSerializer();

        return serializer.Serialize(data.ToDictionary());

    }
}