编译出错，，请各位大哥帮看一下

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, jpeg, ExtCtrls, StdCtrls, Buttons;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Button1: TButton;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Edit3: TEdit;
    Label1: TLabel;
    Image1: TImage;
    Button5: TButton;
    Button6: TButton;
    Button7: TButton;
    Button8: TButton;
    Button9: TButton;
    Button10: TButton;
    Button11: TButton;
    Button12: TButton;
    Button13: TButton;
    Button14: TButton;
    Button15: TButton;
    Button16: TButton;
    SpeedButton1: TSpeedButton;
    SpeedButton2: TSpeedButton;
    SpeedButton3: TSpeedButton;
    SpeedButton4: TSpeedButton;
    Edit4: TEdit;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button16Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
if edit1.text<>''then
begin
edit2.text:='请输入被加数'
end else

ShowMessage('请在输入1中输入数据)'



procedure TForm1.Button2Click(Sender: TObject);
begin
if edit1.text<>''then
begin
edit2.text:='请输入被减数'
end else
begin
ShowMessage('请在输入1中输入数据')
end
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
if edit1.text<>''then
begin
edit2.text:=('请输入被乘数')
end else
begin
ShowMessage('请在输入1中输入数据')
end
end;

procedure TForm1.Button4Click(Sender: TObject);
begin
if edit1.text<>''then
begin
edit2.text:='请输入被除数'
end else
begin
ShowMessage('请在输入1中输入数据')
end
end;

procedure TForm1.Button16Click(Sender: TObject);
begin
if edit2.text='请输入被加数'then
   begin if edit4.text<>''then
   begin
   edit3.Text:=FloatToStr(StrToFloat(edit1.text)+StrToFloat(edit4.text))
   end  else
   ShowMessage('请在输入2中输入数据')
   end
else if edit2.text='请输入被减数'then
        begin if edit4.text<>''then
                 begin
                 edit3.Text:=FloatToStr(StrToFloat(edit1.text)-StrToFloat(edit4.text))
                 end  else
                 ShowMessage('请在输入2中输入数据')
                 end
else if edit2.text='请输入被乘数'then
        begin if edit4.text<>''then
                 begin
                 edit3.Text:=FloatToStr(StrToFloat(edit1.text)*StrToFloat(edit4.text))
                 end  else
                 ShowMessage('请在输入2中输入数据')
                 end
else if edit2.text='请输入被除数'then
        begin if (edit4.text<>'')and(edit4.text<>'0')then
                 begin
                 edit3.Text:=FloatToStr((StrToFloat(edit1.text))/(StrToFloat(edit4.text)))
                 end  else
                 ShowMessage('请在输入2中输入数据或除数不能为0')
                 end



end;

end.
编译后有如下错误
[Error] Unit1.pas(66): ')' expected but 'PROCEDURE' found
[Fatal Error] Project1.dpr(5): Could not compile used unit 'Unit1.pas'
不懂哪错了
请高手指点一下