unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, math;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Edit3: TEdit;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  MyEditCount:integer;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  i, myneweditcount:integer;
const
  NamePrefix = 'Edit';
  NewEdits = 3;
begin
  myneweditcount:=myeditcount+newedits;
  while myeditcount < myneweditcount do begin
    TEdit.Create(Self).Name := NamePrefix + IntToStr(myeditcount+1);
    with TEdit(FindComponent(NamePrefix + IntToStr(myeditcount+1))) do
    begin
      Left := 8;
      Top := 8 + myeditcount * 32;
      Parent := self;
      text:='0';
      taborder:=myeditcount;
    end;

    for i:= 1 to 4 do
      (Findcomponent('Label' + inttostr(i)) as TLabel).top:=(Findcomponent('Label' + inttostr(i)) as TLabel).top+32;

    for i:= 1 to 3 do
      (Findcomponent('Button' + inttostr(i)) as TButton).top:=(Findcomponent('Button' + inttostr(i)) as TButton).top+32;

    form1.Height:=form1.Height+32;

    myeditcount:=myeditcount+1;
  end;
  edit1.SetFocus;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  myeditcount:=3;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  i,k,position:integer;
  erg:extended;
  temp:string;
begin
  erg:=0;

  for i := 1 to myeditcount do begin
    temp:='';
    if pos(',',(Findcomponent('Edit' + inttostr(i)) as TEdit).text) <> 0
    then begin
      position:=pos(',',(Findcomponent('Edit' + inttostr(i)) as TEdit).text);
      for k:=1 to position-1 do
        temp:=temp+(Findcomponent('Edit' + inttostr(i)) as TEdit).text[k];
      temp:=temp+'.';
      for k:=position+1 to length((Findcomponent('Edit' + inttostr(i)) as TEdit).text) do
        temp:=temp+(Findcomponent('Edit' + inttostr(i)) as TEdit).text[k];
      (Findcomponent('Edit' + inttostr(i)) as TEdit).text:=temp;
    end;
  end;

  for i := 1 to myeditcount do
    erg:=erg+strtofloat((Findcomponent('Edit' + inttostr(i)) as TEdit).text);

  label2.Caption:='Ohne MwSt: ' + floattostr(roundto(erg, -2)) + ' €';
  label3.caption:='MwSt: ' + floattostr(roundto(erg*0.16, -2))+ ' €';
  label4.Caption:='Incl MwSt: ' + floattostr(roundto(erg*1.16, -2))+ ' €';
end;

procedure TForm1.Button3Click(Sender: TObject);
var
  i:integer;
begin
  for i:= 1 to myeditcount do
    (Findcomponent('Edit' + inttostr(i)) as TEdit).text:='0';

  Label2.caption:='Ohne MwSt:';
  Label3.caption:='MwSt:';
  label4.caption:='Incl MwSt:';
end;


end.