public ActionResult _AddUserToProject(int Id)
        {
            var users = db.Users.ToList().OrderBy(x => x.Surname);
            var list  = users.Select(x => new SelectListItem()
            {
                Value = x.Id, Text = x.Name + " " + x.Surname
            }).ToList();
            //var contr = db.Projects.Find(Id).Contributors;

            //foreach(var usr in list)
            //{
            //    if (contr.Contains(users.ToList().Find(usr.Value)))
            //    {

            //    }
            //}

            var model = new AddUserToProjectModels
            {
                ProjectId    = Id,
                Users        = list,
                Contributors = db.Projects.Find(Id).Contributors
            };

            model.Contributors = model.Contributors.OrderBy(x => x.Surname).ToList();

            return(PartialView("_AddUserToProject", model));
        }
        public ActionResult _AddUserToProject(AddUserToProjectModels model)
        {
            if (model.UserToAddId == null)
            {
                return(RedirectToAction("ProjectDetails", new { id = model.ProjectId }));
            }

            Project         project   = db.Projects.Find(model.ProjectId);
            ApplicationUser userToAdd = db.Users.Find(model.UserToAddId);

            project.Contributors.Add(userToAdd);
            db.Entry(project).State = System.Data.Entity.EntityState.Modified;
            db.SaveChanges();

            return(RedirectToAction("ProjectDetails", new { id = model.ProjectId }));
        }