OnDocumentComplete: This event fire when the document has reached ReadyState _Complete
Write an OnDocumentComplete event handler to take a specific action when a frame or document is fully loaded into your browser
.For a document without frames, this event occurs once when the document finishes loading.
On a document containing multiple frames, this event occurs once for each frame.
When the multiple-frame document finishes loading, the Web browser fires the event one final time.
In simple words, here is the place to take action when you need to be sure the document is fully loaded. like when you want to hide your Progressbar when the document is loaded or when you want to hande Auto login form like in the folowing examples.


procedure TbrowserFrm.EmbeddedWB1DocumentComplete(Sender: TObject;
  const pDisp: IDispatch; var URL: OleVariant);
begin
     Progressbar1.Visible:=false;
end;
 
//Create AutoLogin for several Website Like: mail.yahoo, kompas.co.id, etc :
//by yhoezt@yahoo.com

//We need two form, : form login and form web browser(Twebbrowser)

//Here the code program :


//Form AutoLogin:

interface

uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, Buttons, StdCtrls, ExtCtrls, Wininet, Registry,
 ShellAPI,DDEMan,MSHTML, FileCtrl,ShlObj,SHDocVw,Unit_con8_b;

type
 TAutoLogin = class(TForm)
   Panel1: TPanel;
   GroupBox1: TGroupBox;
   Panel2: TPanel;
   Label1: TLabel;
   UserTxt: TEdit;
   Label2: TLabel;
   Panel4: TPanel;
   LogBtn: TSpeedButton;
   Panel5: TPanel;
   Panel6: TPanel;
   HistoryBtn: TSpeedButton;
   Panel8: TPanel;
   CloseBtn: TSpeedButton;
   Panel3: TPanel;
   GoURLBtn: TSpeedButton;
   OpenUrlText: TComboBox;
   PassTxt: TEdit;
   procedure GoURLBtnClick(Sender: TObject);
   procedure HistoryBtnClick(Sender: TObject);
   procedure DefaultBtnClick(Sender: TObject);
   procedure CloseBtnClick(Sender: TObject);
   procedure LogBtnClick(Sender: TObject);
 private
   procedure Url_Open;
   procedure Login_Web;
   { Private declarations }
 public
   { Public declarations }
 end;

var
 AutoLogin: TAutoLogin;
 ValueStr: string;
 LinkOpened: integer;
 DDE: TDdeClientConv;
 KeyName: string;
 Reg: TRegistry;

implementation

{$R *.dfm}

function IsWin95: boolean;
var OS: TOSVersionInfo;
begin
   ZeroMemory(@OS,SizeOf(OS));
   OS.dwOSVersionInfoSize:= SizeOf(OS);
   GetVersionEx(OS);
   Result:= (OS.dwMajorVersion>=4) and (OS.dwMinorVersion=0) and
            (OS.dwPlatformId= VER_PLATFORM_WIN32_WINDOWS);
end;

function FuncAvail(_dllname, _funcname: string;var _p: pointer): boolean;
var _lib: tHandle;
begin
  Result := false;
  if LoadLibrary(PChar(_dllname)) = 0 then exit;
  _lib := GetModuleHandle(PChar(_dllname)) ;
  if _lib <> 0 then
  begin
     _p := GetProcAddress(_lib, PChar(_funcname)) ;
     if _p <> NIL then Result := true;
  end;
end;

procedure ConnectedToInternet;
var InetIsOffline : function(dwFlags: DWORD):BOOL; stdcall;
   Lib: string;
begin
   if(IsWin95) then Lib:= 'SHELL32.DLL'
      else Lib:= 'URL.DLL';
   if FuncAvail(Lib, 'InetIsOffline',@InetIsOffline) then
   begin
      if (InetIsOffLine(0)) then
         ShowMessage('Not Connected')
      else
          ShowMessage('Connected!');
   end;
end;

function IsUrlValid(Url: string): boolean;
var hINet: HINTERNET;
   hConnect: HINTERNET;
   infoBuffer: array[0..512] of Char;
   dummy: DWORD;
   bufLen: DWORD;
   okay: LongBool;
   reply: string;
begin
   hINet:= InternetOpen(PChar(Application.Title),
           INTERNET_OPEN_TYPE_PRECONFIG_WITH_NO_AUTOPROXY,nil,nil,0);
   hConnect:= InternetOpenUrl(hINet,PChar(Url),nil,0,INTERNET_FLAG_NO_UI,0);
   if not Assigned(hConnect) then
       Result:= True  //seharusnya False , nanti diganti
   else
   begin
       dummy:= 0;
       bufLen:= Length(infoBuffer);
       okay:= HttpQueryInfo(hConnect,HTTP_QUERY_STATUS_CODE,@infoBuffer[0],
                            bufLen,dummy);
       if not(okay) then
               Result:= False
       else
       begin
           reply:= infoBuffer;
           if (reply='200') then Result:= True
           else if (reply='401') then Result:= True
           else if (reply='404') then Result:= False
           else if (reply='500') then Result:= False
           else Result:= False;
       end;
       InternetCloseHandle(hConnect);
   end;
   InternetCloseHandle(hINet);
end;

procedure DeleteIECache;
var
 lpEntryInfo: PInternetCacheEntryInfo;
 hCacheDir: LongWord;
 dwEntrySize: LongWord;
begin
 dwEntrySize := 0;
 FindFirstUrlCacheEntry(nil, TInternetCacheEntryInfo(nil^), dwEntrySize);
 GetMem(lpEntryInfo, dwEntrySize);
 if dwEntrySize > 0 then lpEntryInfo^.dwStructSize := dwEntrySize;
 hCacheDir := FindFirstUrlCacheEntry(nil, lpEntryInfo^, dwEntrySize);
 if hCacheDir <> 0 then
 begin
   repeat
     DeleteUrlCacheEntry(lpEntryInfo^.lpszSourceUrlName);
     FreeMem(lpEntryInfo, dwEntrySize);
     dwEntrySize := 0;
     FindNextUrlCacheEntry(hCacheDir, TInternetCacheEntryInfo(nil^), dwEntrySize);
     GetMem(lpEntryInfo, dwEntrySize);
     if dwEntrySize > 0 then lpEntryInfo^.dwStructSize := dwEntrySize;
   until not FindNextUrlCacheEntry(hCacheDir, lpEntryInfo^, dwEntrySize);
 end;
 FreeMem(lpEntryInfo, dwEntrySize);
 FindCloseUrlCache(hCacheDir);
end;

procedure TAutoLogin.Login_Web;
begin
   UserTxt.Enabled:= True;
   PassTxt.Enabled:= True;
   LogBtn.Enabled:= True;
   UserTxt.SetFocus;
end;

procedure TAutoLogin.Url_Open;
begin
   if(IsUrlValid(OpenUrlText.Text)) then
   begin
      if(Application.MessageBox('Login?','Confirmation',MB_YESNO))=IDYES then
      Login_Web
      else
      begin
          ShellExecute(self.WindowHandle,'open',PChar(OpenUrlText.Text),
                       nil,nil, SW_MINIMIZE);
          OpenUrlText.Clear;
      end;
   end
   else ShowMessage('URL is Not Valid');
end;

procedure TAutoLogin.GoURLBtnClick(Sender: TObject);
begin
   ConnectedToInternet;
   if(OpenUrlText.Text<>'') then Url_Open
   else
   begin
       ShowMessage('U Must Fill Url Text First');
       OpenUrlText.SetFocus;
   end;
end;

procedure TAutoLogin.HistoryBtnClick(Sender: TObject);
begin
   if(Application.MessageBox('Delete History?','Confirmation',MB_YESNO))=IDYES then
   begin
       DeleteIECache;
   end;
end;

procedure TAutoLogin.DefaultBtnClick(Sender: TObject);
begin
   AutoLogin.Hide;
   WebSiteDef.Show;
end;

procedure TAutoLogin.CloseBtnClick(Sender: TObject);
begin
   Close;
   Application.Terminate;
end;

procedure TAutoLogin.LogBtnClick(Sender: TObject);
begin
   if(UserTxt.Text='')then
   begin
       ShowMessage('U Must Fill UserName');
       UserTxt.SetFocus;
   end
   else if(PassTxt.Text='')then
   begin
       ShowMessage('U Must Fill Password');
       PassTxt.SetFocus;
   end
   else
   begin
       FormLogin.Show;
       FormLogin.WebBrowser1.Navigate(OpenUrlText.Text);
   end;
end;

end.


//FormLogin (WebBrowser) :

interface

uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, Buttons, OleCtrls, SHDocVw, ExtCtrls, MSHTML, ShellApi;

type
 TFormLogin = class(TForm)
   Panel2: TPanel;
   CloseLogin: TSpeedButton;
   WebBrowser1: TWebBrowser;
   procedure CloseLoginClick(Sender: TObject);
   procedure WebBrowser1DocumentComplete(Sender: TObject;
     const pDisp: IDispatch; var URL: OleVariant);
 private
   { Private declarations }
 public
   { Public declarations }
 end;

var
 FormLogin: TFormLogin;

implementation

{$R *.dfm}
uses Unit_con8;

procedure TFormLogin.WebBrowser1DocumentComplete(Sender: TObject;
 const pDisp: IDispatch; var URL: OleVariant);

var iDoc: IHtmlDocument2;
 i: integer;
 ov: OleVariant;
 iDisp: IDispatch;
 iColl: IHTMLElementCollection;
 iInputElement: IHTMLInputElement;

begin
 WebBrowser1.ControlInterface.Document.QueryInterface(IID_IHTMLDocument, iDoc);
 if not assigned(iDoc) then
 begin
   ShowMessage(' Nothing dowloaded ');
   Exit;
 end;
 ov := 'INPUT';
 IDisp := iDoc.all.tags(ov);
 if assigned(IDisp) then
 begin
   IDisp.QueryInterface(IID_IHTMLElementCollection, iColl);
   if assigned(iColl) then
   begin
     for i := 1 to iColl.Get_length do
     begin
       iDisp := iColl.item(pred(i), 0);
       iDisp.QueryInterface(IID_IHTMLInputElement, iInputElement);
       if assigned(iInputElement) then
       begin
         if (iInputElement.type_='text') or (iInputElement.name='user')
         then iInputElement.value:= AutoLogin.UserTxt.Text;
         if (iInputElement.type_= 'password') or (iInputElement.name='password')
            or (iInputElement.name='passwd')
         then iInputElement.value:= AutoLogin.PassTxt.Text;
         Caption := AutoLogin.OpenUrlText.Text;
       end;
     end;
   end;
 end;
 with AutoLogin do
 begin
     UserTxt.Clear;
     PassTxt.Clear;
     UserTxt.Enabled:= False;
     PassTxt.Enabled:= False;
     LogBtn.Enabled:= False;
     OpenUrlText.Clear;
 end;
end;

procedure TFormLogin.CloseLoginClick(Sender: TObject);
begin
   FormLogin.Hide;
   AutoLogin.Show;
end;


end.