Как выполнить JavaScript-функцию?

uses 
  MSHTML_TLB, SHDocVw, ShellAPI; 
 
// function to execute a script function 
 
function ExecuteScript(doc: IHTMLDocument2; script: string; language: string): Boolean; 
var 
  win: IHTMLWindow2; 
  Olelanguage: Olevariant; 
begin 
  if doc <> nil then 
  begin 
    try 
      win := doc.parentWindow; 
      if win <> nil then 
      begin 
        try 
          Olelanguage := language; 
          win.ExecScript(script, Olelanguage); 
        finally 
          win := nil; 
        end; 
      end; 
    finally 
      doc := nil; 
    end; 
  end; 
end; 
 
// 2 Examples how to login to gmx homepage 
 
procedure FillInGMXForms(WB: ShDocVW_TLB.IWebbrowser2; IDoc1: IHTMLDocument2; 
  Document: Variant; AKennung, APasswort: string); 
const 
  IEFields: array[1..4] of string = ('INPUT', 'text', 'INPUT', 'password'); 
var 
  IEFieldsCounter: Integer; 
  i: Integer; 
  m: Integer; 
  ovElements: OleVariant; 
begin 
  if Pos('GMX - Homepage', Document.Title) <> 0 then 
 
    while WB.ReadyState <> READYSTATE_COMPLETE do 
      Application.ProcessMessages; 
 
  // count forms on document and iterate through its forms 
  IEFieldsCounter := 0; 
  for m := 0 to Document.forms.Length - 1 do 
  begin 
    ovElements := Document.forms.Item(m).elements; 
 
    // iterate through elements 
    for i := ovElements.Length - 1 downto 0 do 
    begin 
      try 
        // if input fields found, try to fill them out 
        if (ovElements.item(i).tagName = IEFields[1]) and 
          (ovElements.item(i).type = IEFields[2]) then 
        begin 
          ovElements.item(i).Value := AKennung; 
          Inc(IEFieldsCounter); 
        end; 
 
        if (ovElements.item(i).tagName = IEFields[3]) and 
          (ovElements.item(i).type = IEFields[4]) then 
        begin 
          ovElements.item(i).Value := APasswort; 
          Inc(IEFieldsCounter); 
        end; 
      except 
        // failed... 
      end; 
    end; { for i...} 
  end;  { for m } 
  // if the fields are filled in, submit. 
  if IEFieldsCounter = 3 then ExecuteScript(iDoc1, 'document.login.submit()', 
      'JavaScript'); 
end; 
 
function LoginGMX_IE(AKennung, APasswort: string): Boolean; 
var 
  ShellWindow: IShellWindows; 
  WB: ShDocVW_TLB.IWebbrowser2; 
  spDisp: IDispatch; 
  IDoc1: IHTMLDocument2; 
  Document: Variant; 
  k: Integer; 
begin 
  ShellWindow := CoShellWindows.Create; 
  // get the running instance of Internet Explorer 
  for k := 0 to ShellWindow.Count do 
  begin 
    spDisp := ShellWindow.Item(k); 
    if spDisp = nil then Continue; 
    // QueryInterface determines if an interface can be used with an object 
    spDisp.QueryInterface(iWebBrowser2, WB); 
    if WB <> nil then 
    begin 
      WB.Document.QueryInterface(IHTMLDocument2, iDoc1); 
      if iDoc1 <> nil then 
      begin 
        WB := ShellWindow.Item(k) as ShDocVW_TLB.IWebbrowser2; 
        Document := WB.Document; 
        // if GMX page... 
        FillInGMXForms(WB, IDoc1, Document, AKennung, APasswort); 
      end;  { idoc <> nil } 
    end; { wb <> nil } 
  end;  { for k } 
end; 
 
// Example 1: Navigate to the gmx homepage in the IE browser an login 
procedure TForm1.Button1Click(Sender: TObject); 
begin 
  ShellExecute(Handle, 
    'open', 
    'http://www.gmx.ch', 
    nil, 
    nil, 
    SW_SHOW); 
  Sleep(2000); 
  LoginGMX_IE('user@gmx.net', 'pswd'); 
end; 
 
 
// Example 2: navigate to the gmx homepage in the Webbrowser an login 
procedure TForm1.Button2Click(Sender: TObject); 
var 
  IDoc1: IHTMLDocument2; 
  Web: ShDocVW_TLB.IWebBrowser2; 
begin 
  Webbrowser1.Navigate('http://www.gmx.ch'); 
  while Webbrowser1.ReadyState <> READYSTATE_COMPLETE do 
    Application.ProcessMessages; 
  Webbrowser1.Document.QueryInterface(IHTMLDocument2, iDoc1); 
  Web := WebBrowser1.ControlInterface; 
  FillInGMXForms(Web, iDoc1, Webbrowser1.Document, 'user@gmx.net', 'pswd'); 
end;

Взято с сайта https://www.swissdelphicenter.ch/en/tipsindex.php