code: function(cell) {
      var elCell = this.getTdEl(cell);
      if(elCell) {
          var elPreviousRow = this.getPreviousTrEl(elCell);
          if(elPreviousRow) {
              return elPreviousRow.cells[elCell.cellIndex];
          }
      }
      YAHOO.log("Could not get above TD element for cell " + cell, "info", this.toString());
      return null;
  }
docs: Returns DOM reference to the above TD element from the given cell, or null.
  
  @method getAboveTdEl
  @param cell {HTMLElement | String | Object} DOM element reference or string ID, or
  object literal of syntax {record:oRecord, column:oColumn} from which to get next TD element.
  @return {HTMLElement} Reference to next TD element, or null.