public ActionResult AcceptUser(string id) {
ApplicationDbContext db = new ApplicationDbContext();
ApplicationUser user = db.Users.Find(id);
IdentityManager im = new IdentityManager();
im.RemoveFromRole(user.Id, "Waiting");
im.AddUserToRoleByUsername(user.UserName, "User");
TempData["notice"] = "User accepted!";
return RedirectToAction("WaitingUsers");
}