public ActionResult AssignUsers(int Id)
        {
            var project = db.Projects.Find(Id);
            var user    = new AssignUsersToProjVM();

            user.Id            = Id;
            user.userList      = new MultiSelectList(db.Users, "Id", "FirstName", user.selectedUsers);
            user.projectName   = project.Name;
            user.selectedUsers = projectHelper.ListUsersInProject(project.Id).ToList();
            return(View(user));
        }
        public ActionResult AssignUsers(AssignUsersToProjVM model)
        {
            var x = db.Projects.Find(model.Id);

            foreach (var item in db.Users.Select(u => u.Id).ToList())
            {
                projectHelper.RemoveProjectUser(x.Id, item);
            }
            foreach (var item in model.selectedUsers)
            {
                projectHelper.AssignProjectUser(x.Id, item);
            }

            return(RedirectToAction("Details", "Projects", new { id = model.Id }));
        }