Jednoduchy priklad:

Nova aplikace, pridam form, takze budu mit Form1 (unit1) a Form2 (unit2)
V Unit1 do casti implementation do uses pridam Unit2.
Na Form1 dam tlacitko a do nej kod:

implementation

uses Unit2;

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  Form2 := TForm2.Create(self);
  Form2.Parent := Form1;
  Form2.Left := 40;
  Form2.Top := 40;
  Form2.Show;
end;