EnsureMinimumNumberOfRows.js

////////////////////////////////////////////////////////////////////////////////
// EnsureMinimumNumberOfRows(element, params) - ensures a table will have a minimum
// ==========================================   number of visible rows.   
// Supported params are:  
//  numberOfRows - gives the minimum number of rows that will appear 
//  rowHeight - height, in pixels for added rows
// *NOTE: Does not support empty tables 
////////////////////////////////////////////////////////////////////////////////
function EnsureMinimumNumberOfRows(element, params) { 
  var minimumNumberOfRows  = params.numberOfRows || 10,        // default minimumNumberOfRows is 10
      rowHeight            = params.rowHeight    || 30,        // default rowHeight (for new rows) is 30px
      oTable = $(element).select('div.resultList table')[0],   // Get the first element as $(element).select returns an array 
      numberOfRowsToInsert = minimumNumberOfRows - oTable.rows.length + 1;
 
  if (numberOfRowsToInsert > 0) {
    var clonedRow   = oTable.rows[ oTable.rows.length - 1 ]
        clonedCells = clonedRow.getElementsByTagName('td');
    for (var i=0;i<numberOfRowsToInsert;i++) {  
      var oRow = document.createElement("TR");
      for (j=0;j<clonedCells.length;j++) {
        var oCell = clonedCells[j].cloneNode(false);
        oCell.style.height = rowHeight + "px";  
        oCell.appendChild( document.createTextNode("\u00a0") );
        oRow.appendChild(oCell);
      }
      oTable.appendChild( oRow );  
    }
  }
}

Here I present a useful function called "EnsureMinimumNumberOfRows".

This function operates on a table and effectively clones the last row in the table a given number of times to ensure that a minimum number of rows exist within the table. it does not clone the contetns of the cells, but rather the nodes themselves and their classnames (by way of cloneNode(false).