帮我看看，为什么出错

Question

为什么总是冒出CPU错误，且函数未执行完就返回了！
private
    { Private declarations }
  public
    { Public declarations }
  end;  TModPas=Function(OldPwd:PChar;NewPwd:PChar):Boolean;var
  Form1: TForm1;
  ModPassWord:TModPas;implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
var
  xx1,xx2:PChar;
  hh:thandle;
begin
    hh:=LoadLibrary(PChar('xpformdll.dll'));
      if hh<>0 then
        @ModPassWord:=GetProcAddress(HH,'ModPassWord');
        if (@ModPassWord)<>nil then
          if  TModPas(ModPassWord)(xx1,xx2) then
            showmessage(xx1)
        else
            showmessage('nopt');
    FreeLibrary(hh);
end;