procedure TMainFrm.CalculateRecordSizeClick(Sender: TObject);
var
 MaxRecs, RecSize, RecsPerBlock, FreeSpace: Longint;
 i: Integer;
begin
 RecSize := 0;
 with StrucGrid do
 begin
  for i := 0 to pred(RowCount) do
  begin
  case Cells[1, i][1] of
  'A': RecSize := RecSize + StrToInt(Cells[2, i]);
  'D', 'T', 'I', '+': RecSize := RecSize + 4;
  'N', '$', 'Y', '@': RecSize := RecSize + 8;
  'M', 'B', 'F', 'O', 'G': RecSize := RecSize + 10 + StrToInt(Cells[2, i]);
  'S': RecSize := RecSize + 2;
  'L': RecSize := RecSize + 1;
  end;
  end;
 end;
 RecsPerBlock := (SpinEdit2.Value - 6) div RecSize;
 FreeSpace := (SpinEdit2.Value - 6) - (RecSize * RecsPerBlock);
 MaxRecs := 65536 * RecsPerBlock;
 ShowMessage('Record Size is: ' + IntToStr(RecSize) + ' bytes' + #13#10
  + 'Records per Block: ' + IntToStr(RecsPerBlock) + #13#10
  + 'Unused Space per Block: ' + IntToStr(FreeSpace) + ' bytes' + #13#10
  + 'Max No of Records in Table: ' + FormatFloat('###############,', MaxRecs));
end;