I have function like this which show database records in default order i would like to show it descending order. Just let me where do i need to write commmand to to sort the records.

Code:
function query_split($sqlu) {
	$sql = str_replace('#__', DB_PREFIX, $sqlu);
	
	  if ( (xc_request('page')) && (xc_request('page') !== '1') && (is_numeric(xc_request('page'))) ) {
	  	$page = ((int)xc_request('page') - 1);
		
		$this->page = ((int)xc_request('page'));
		$page_sql = ($page * MAX_DISPLAY_SEARCH_RESULTS);
	  } else {
	    $page = '0';
		$this->page = '1';
		$page_sql = '0';
	  }
	  
	  $pos_to = strlen($sql);
      $pos_from = strpos($sql, ' from', 0);
		
	  $pos_group_by = strpos($sql, ' group by', $pos_from);
      if (($pos_group_by < $pos_to) && ($pos_group_by != false)) $pos_to = $pos_group_by;

      $pos_having = strpos($sql, ' having', $pos_from);
      if (($pos_having < $pos_to) && ($pos_having != false)) $pos_to = $pos_having;

      $pos_order_by = strpos($sql, ' order by', $pos_from);
      if (($pos_order_by < $pos_to) && ($pos_order_by != false)) $pos_to = $pos_order_by;
		
      //let's add one time calling for numrows
  
	    $reviews_count_query = @mysql_query("select count(*) as total " . substr($sql, $pos_from, ($pos_to - $pos_from)));
	    $reviews_count = @mysql_fetch_object($reviews_count_query);
        $query_num_rows = $reviews_count->total;
	    @mysql_free_result($reviews_count_query);
	  
	  	  
	   $resource = @mysql_query ($sql . " limit " . $page_sql . ", " . MAX_DISPLAY_SEARCH_RESULTS );

	    $before = ($page * MAX_DISPLAY_SEARCH_RESULTS);
		if ($query_num_rows < $before) {
		  $this->batch_from = '0';
		} else {
		  $this->batch_from = $before;
		}
		if ($query_num_rows < (($page * MAX_DISPLAY_SEARCH_RESULTS) + MAX_DISPLAY_SEARCH_RESULTS)) {
		  $this->batch_to = $query_num_rows;
		  

		} else {
		  $this->batch_to = ($page * MAX_DISPLAY_SEARCH_RESULTS) + MAX_DISPLAY_SEARCH_RESULTS;
		}
		$this->batch_size = $query_num_rows;

	  if (!$resource) { 
            $this->eroarea = mysql_error(); 
			die ($this->Error());
            return 0; // error 
        } 
		$this->num_rows = $query_num_rows;
      return $resource;
	}
thanks in advance