docs: function _fnNodeToColumnIndex( oSettings, iRow, n )
  		{
  			var anCells = _fnGetTdNodes( oSettings, iRow );
  		
  			for ( var i=0, iLen=oSettings.aoColumns.length ; i<iLen ; i++ )
  			{
  				if ( anCells[i] === n )
  				{
  					return i;
  				}
  			}
  			return -1;
  		}