public ActionResult AssignRole(string Id)
        {
            var model          = new UserRoleViewModel();
            var userRoleHelper = new UserRoleHelper();

            model.Id       = Id;
            model.UserName = db.Users.FirstOrDefault(p => p.Id == Id).UserName;
            var roles     = userRoleHelper.GetAllroles();
            var userRoles = userRoleHelper.GetUserRoles(Id);

            model.Roles = new MultiSelectList(roles, "Name", "Name", userRoles);

            return(View(model));
        }