var
  wDoc:IHTMLDocument2;

  wc:IHTMLWindow2;
  Dispatch:IDispatch;
begin
   //遍历emWb:TEmbeddedWB的Frames
   if emWb <> nil then
   begin

     wDoc := ((emWb.Document as IHTMLDocument2));
     if Assigned(wDoc) then
     begin
           for i=0 to wDoc.frams.length -1 do //遍历

           begin

                Dispatch:= wd.frames.item(0);
                Dispatch.QueryInterface(IHTMLWindow2,wc); //获得子frame的IHTMLWindow2对象

                wc.execScript('logout()','JavaScript');//执行js
          end;                    
      end;
   end;
 end;