delphi登录窗体代码

点击住窗体按钮后，显示登录窗体，输入正确的用户名和密码后，进入相应模块。下面的是代码：
登录窗体的代码：var
  frmlogin: Tfrmlogin;
  Flag:Boolean;implementation
Uses datam;{$R *.dfm}procedure Tfrmlogin.ButtoncancleClick(Sender: TObject);
begin
Flag:=False;
Close;
end;procedure Tfrmlogin.ButtonenterClick(Sender: TObject);
begin
try
with Data do
begin
 ADOQuerylogin.Close;
 ADOQuerylogin.SQL.Clear;
   ADOQuerylogin.SQL.Add('select * from users where YHM="'+Editname.Text+'"');
   {添加查找用户的语句}
   ADOConnectionlogin.Connected:=True; {连接数据路}
   ADOQuerylogin.Open;                     {打开ADOQuery}
   end
   except
   begin
   MessageDlg('Connect Database Error!',mtError,[mbOK],0);
   {如果打不开数据库则提示}
   close;
   end
   end;
   if Data.ADOQuerylogin.RecordCount=1 then
   if Data.ADOQuerylogin['MM']=Editpass.Text then
   begin
   Flag:=True     {密码正确}
   end
   else begin
   Flag:=False;      {密码不正确}
   MessageDlg('Passwoed Error!',mtError,[mbOK],0);
   end
   else begin
   Flag:=False;    {没有找到用户}
   MessageDlg('Username Error!',mtError,[mbOK],0);
   end;
   close;
end;
end.
主界面的代码：procedure Tfmain.ButtonmenzhenClick(Sender: TObject);
begin
flogin.ShowModal;                         {显示登录窗体}
if Data.ADOClogin.Connected then          {判断登录是否成功}
if (Data.ADOQlogin['YHQX']=1) or
(Data.ADOQlogin['YHQX']=10) then begin     {如果登录成功则判断权限}
Data.ADOQlogin.Edit;                       {加入登录时间}
Data.ADOQlogin['DLSJ']:=Now;
Data.ADOQlogin.Post;
Application.CreateForm(Tfrmmenzhen; frmmenzhen);     {创建窗体}
flogin.Hide;                                          {隐藏登录窗体}
fmain.Hide;                                           {隐藏主窗体}
frmmenzhen.ShowModal;                                  {显示门诊管理窗体}
end
else
MessageDlg('you not have Authorization!',mtError,[mbOK],0);  {没有权限}
end;procedure Tfmain.ButtontuichuClick(Sender: TObject);
begin
Application.Terminate;
end;procedure Tfmain.ButtonzhuyuanClick(Sender: TObject);
begin
flogin.ShowModal;
 if Data.ADOClogin.Connected then
 if (Data.ADOQlogin['YHQX']=2) or
(Data.ADOQlogin['YHQX']=10) then begin
 Data.ADOQlogin.Edit;
  Data.ADOQlogin['DLSJ']:=Now;
  Data.ADOQlogin.Post;
  Application.CreateForm(Tfrmmenzhen; frmmenzhen);
  flogin.Hide;
fmain.Hide;
frmmenzhen.ShowModal;
end
else
MessageDlg('you not have Authorization!',mtError,[mbOK],0);
end;procedure Tfmain.ButtonyaopinClick(Sender: TObject);
begin
flogin.ShowModal;
if Data.ADOClogin.Connected then
 if (Data.ADOQlogin['YHQX']=3) or
(Data.ADOQlogin['YHQX']=10) then begin
 Data.ADOQlogin.Edit;
  Data.ADOQlogin['DLSJ']:=Now;
  Data.ADOQlogin.Post;
  Application.CreateForm(Tfrmyaopin; frmyaopin);
  flogin.Hide;
fmain.Hide;
frmyaopin.ShowModal;
end
else
MessageDlg('you not have Authorization!',mtError,[mbOK],0);
end;end.