show computer name and sqlserver name

DataTable table = SqlDataSourceEnumerator.Instance.GetDataSources();
           foreach (DataRow server in table.Rows)
           {
               foreach (DataColumn col in table.Columns)
               {
                   cmbshowallsqlserver.Items.Add(string.Format("{0}\\{1}", server[table.Columns["ServerName"]], server[table.Columns["InstanceName"]]));
               }
           }