//[SiteMapPage(false)]
 public AjaxPartialViewResult MyFormPartial(MyFormVM vm)
 {
     vm.AddModelError(ModelState, m=> m.MyTextInput, "Test Invalid data");
     vm.AddModelError(ModelState, m => m.MyNestedItem.Text, "Invalid Nested Item");
     vm.AddModelError(ModelState, m => m.MySelect, "Invalid Select Item");
     return AjaxPartialView("MyFormPartial", vm);
 }
 public ActionResult MyForm(MyFormVM vm)
 {
     if (ModelState.IsValid)
     {
         return RedirectToAction("Index");
     }
     else
     {
         return View(vm);
     }
 }