Автор: http://www.swissdelphicenter.ch

{
  This example shows how to automatically fill in a search string
  in the "Search Tip" page and click the search button.
}

uses
  MSHTML_TLB;

// first navigate to tipspage

procedure TForm1.Button1Click(Sender: TObject);
begin
  Webbrowser1.Navigate('http://www.swissdelphicenter.ch/en/tipsuchen.php');
end;

// Try to access IE instance and fill out the search field with
// a text and click the search button

procedure TForm1.Button3Click(Sender: TObject);
var
  hIE: HWND;
  ShellWindow: IShellWindows;
  WB: IWebbrowser2;
  spDisp: IDispatch;
  IDoc1: IHTMLDocument2;
  Document: Variant;
  k, m: Integer;
  ovElements: OleVariant;
  i: 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 IWebbrowser2;
        begin
          Document := WB.Document;

          // count forms on document and iterate through its forms
          for m := 0 to Document.forms.Length - 1 do
          begin
            ovElements := Document.forms.Item(m).elements;
            // iterate through elements
            for i := 0 to ovElements.Length - 1 do
            begin
              // when input fieldname is found, try to fill out
              try
                if (CompareText(ovElements.item(i).tagName, 'INPUT') = 0) and
                  (CompareText(ovElements.item(i).type, 'text') = 0) then
                begin
                  ovElements.item(i).Value := 'FindWindow';
                end;
              except
              end;
              // when Submit button is found, try to click
              try
                if (CompareText(ovElements.item(i).tagName, 'INPUT') = 0) and
                  (CompareText(ovElements.item(i).type, 'SUBMIT') = 0) and
                  (ovElements.item(i).Value = 'Search') then
                    // Suchen fьr German
                begin
                  ovElements.item(i).Click;
                end;
              except
              end;
            end;
          end;
        end;
      end;
    end;
  end;
end;