Unsatisfied forward or external declaration 错误分析

 1 type
 2   TForm1 = class(TForm)
 3  　 ...
 4     procedure PanelClick(Sender:Tobjcet); //过程声明
 5 
 6   private
 7     { Private declarations }
 8   public
 9     { Public declarations }
10   end;
11 
12  var
13   Form1: TForm1;
14 
15  implementation
16 
17 {$R *.dfm}
18 procedure PanelClick(Sender:Tobjcet);　　//Error,出错了!
19   ...
20 
21 
22 
23 procedure TForm1.PanelClick(Sender:Tobjcet);　　//只需加个TForm1就OK了呵呵!
24   ...
25 
26