public IActionResult AssignTo(int projectId, string employeeId) { if (ModelState.IsValid) { if (projectDataService.IsEmployeeInProject(employeeId, projectId)) { ModelState.AddModelError("EmployeeId", "This employee is already in this project"); var model = new EmployeeProjectModel { employeeId = employeeId }; return(RedirectToAction("Assign", "Project", model)); } projectDataService.Assign(employeeId, projectId); return(RedirectToAction("Index", "Home")); } return(RedirectToAction("Assign", "Project")); }