Add membership verification

WebCms/Views/MacroPartials/Membership/Register.cshtml

@@ -14,6 +14,15 @@
     Html.RequiresJs("~/scripts/jquery.validate.unobtrusive.min.js", 2);
 
     Html.RequiresJs("~/scripts/Register.js");
+
+    var user = Membership.GetUser();
+    if (user != null)
+    {
+        TempData["StatusMessage"] = "You are already logged in, " + user.UserName;
+        TempData["StatusMessage-Type"] = "alert-danger";
+
+        // todo: redirect
+    }
 }
 
 <div class="container mt-5">