Code:

procedure TForm1.Button1Click(Sender: TObject);

var

Document: IHTMLDocument2;

rbTestList: IHTMLElementCollection;

rbTest: IHTMLOptionButtonElement;

I: Integer;

begin

// Get a reference to the document

Document := WebBrowser1.Document as IHTMLDocument2;

// Get a reference to input-control (Radiobutton)

rbTestList := Document.all.item('rating', EmptyParam) as IHTMLElementCollection;

// Get current values.

for I := 0 to rbTestList.Length - 1 do

begin

   // reference to the i. RadioButton

   rbTest := rbTestList.item(I, EmptyParam) as IHTMLOptionButtonElement;

   // Show a message if radiobutton is checked

   if rbTest.Checked then

     ShowMessageFmt('Der RadioButton mit dem Wert %s' +

       ' ist ausgewahlt!', [rbTest.Value]);

end;

// Set new values

for I := 0 to rbTestList.Length - 1 do

begin

   // reference to the i. RadioButton

   rbTest := rbTestList.item(I, EmptyParam) as IHTMLOptionButtonElement;

   // check radiobutton with value 3.

   if rbTest.Value = '3' then

     rbTest.Checked := True;

end;

end;