public ActionResult AddUser(int AddUserProjectID, List<string> SelectedUnassignedUsers) { if (ModelState.IsValid) { //Instantiate the helper and find the user in the DB ProjectsHelper helper = new ProjectsHelper(db); var project = db.Projects.Find(AddUserProjectID); //ADD NEW USER(S) if(SelectedUnassignedUsers != null) { foreach (var u in SelectedUnassignedUsers) { //If the user isn't assigned to this project if (!helper.HasProject(u, AddUserProjectID)) { //Add the user to the project helper.AssignUser(u, AddUserProjectID); } } db.Entry(project).State = EntityState.Modified; db.SaveChanges(); return RedirectToAction("Index"); } } return RedirectToAction("Index"); }