docs: function _fnColumnOrdering ( oSettings )
  		{
  			var sNames = '';
  			for ( var i=0, iLen=oSettings.aoColumns.length ; i<iLen ; i++ )
  			{
  				sNames += oSettings.aoColumns[i].sName+',';
  			}
  			if ( sNames.length == iLen )
  			{
  				return "";
  			}
  			return sNames.slice(0, -1);
  		}