func: function unsetRegionForSale(
          uint _start_section_index,
          uint _end_section_index
      ) {
          if(_start_section_index > _end_section_index) throw;
          if(_end_section_index > 9999) throw;
          uint x_pos = _start_section_index % 100;
          uint base_y_pos = (_start_section_index - (_start_section_index % 100)) / 100;
          uint x_max = _end_section_index % 100;
          uint y_max = (_end_section_index - (_end_section_index % 100)) / 100;
          while(x_pos <= x_max)
          {
              uint y_pos = base_y_pos;
              while(y_pos <= y_max)
              {
                  Section section = sections[x_pos + (y_pos * 100)];
                  if(section.owner == msg.sender)
                  {
                      section.for_sale = false;
                      section.price = 0;
                      Delisted(x_pos + (y_pos * 100));
                  }
                  y_pos++;
              }
              x_pos++;
          }
      }