                '">' +
                   '<a href="' + url + '">' +
                   builder +
                   '</a></th>';
            document.write(s);
          }
          document.write('</tr>');
        }
        function write_graphs_header_row() {
          document.write('<tr><th>&nbsp;</th>');
          for (var bindex=0; bindex < builder_list.length; bindex++) {
            for (var gindex=0; gindex < graphs_list.length; gindex++) {
              graph = graphs_list[gindex];
              