procedure TForm1.Edit1Click(Sender: TObject);
begin
  TEdit(sender).SelLength:=1;
  if Pos('.',TEdit(sender).SelText)>0 then
  begin
    TEdit(sender).SelStart:=TEdit(sender).SelStart+1 ;
  end;

end;

procedure TForm1.Edit1Change(Sender: TObject);
begin
  if Pos('.',copy(TEdit(sender).Text,TEdit(sender).SelStart,2))>0 then
  begin
    TEdit(sender).SelStart:=TEdit(sender).SelStart+1;
  end;
  TEdit(sender).SelLength:=1;
  TEdit(sender).Text:=FormatFloat('000.00',StrToFloat(TEdit(sender).Text))  ;
end;

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin

if not (key in [#8,'0'..'9','.']) then
  begin
    key:=chr(0);
  end
  else
  begin
    if (key in ['.']) and (pos('.',TEdit(sender).text)>0) then
    begin
    key:=chr(0);
    end;
  end;
end;

procedure TForm1.Edit1Exit(Sender: TObject);
begin
  if StrToFloat(TEdit(sender).Text)>100 then
  begin
    Application.MessageBox('輸入數值大于100％，請重新輸入！','提示',MB_OK+MB_ICONWARNING+MB_DEFBUTTON1+MB_SYSTEMMODAL);
    TEdit(sender).SetFocus;
  end;
end;