Using C#, please help with fixing/resolving the namespace issues in this code and ensure that the CRUD views are correct. Also ensure that any directive or assembly references are in place.

using System; using System.Collections.Generic; using System.Diagnostics.Contracts; using ExamsAndAverages.Models; namespace ExamsAndAverages.Controllers { public class ExamsAndAverages { static int uniqueID = 1; static List testEntryList = new List(); public ActionResult Index() { ViewBag.Message = "Welcome to Exams and Averages:"; return View(); } public ActionResult About() { ViewBag.Message = "About Exams and Averages:"; return View(); } public ActionResult Contact() { ViewBag.Message = "Your contact page."; return View(); } public ActionResult List() { ViewBag.Message = "The List of the Exams:"; return View(testEntryList); } public ActionResult Details(int id) { ViewBag.Message = "Details of this Exam:"; TestEntry entry = null; foreach (TestEntry e in testEntryList) { if (id == e.ID) { entry = e; break; } } return View(entry); } public ActionResult Create() { ViewBag.Message = "Fill in the Exam's Name:"; return View(); } [HttpPost] public ActionResult Create(TestEntry entry) { if (!ModelState.IsValid) { return View("Create", entry); } testEntryList.Add(new TestEntry(entry.Name, ++uniqueID)); return RedirectToAction("List"); } public ActionResult Edit(int ID) { ViewBag.Message = "Add New Score:"; TestEntry theEntry = null; foreach (TestEntry e in testEntryList) { if (e.ID == ID) { theEntry = new TestEntry(e.Name, ID); break; } } if (theEntry == null) return RedirectToAction("Error"); else { ViewBag.Message = "Add New " + theEntry.Name + " Score:"; return View(theEntry); } } [HttpPost] public ActionResult Edit(TestEntry entry) { Contract.Ensures(Contract.Result() != null); if (!ModelState.IsValid) { ViewBag.Message = "There was an editing error:"; return View("Edit", entry); } foreach (TestEntry e in testEntryList) { if (e.ID == entry.ID) { e.Sum += entry.Sum; e.Amount++; break; } } return RedirectToAction("List"); } public ActionResult Delete(int ID) { TestEntry theEntry = null; ViewBag.Message = "Delete the following Exam:"; foreach (TestEntry e in testEntryList) { if (e.ID == ID) { theEntry = e; break; } } if (theEntry == null) return RedirectToAction("Error"); else return View(theEntry); } [HttpPost] public ActionResult Delete(TestEntry entry) { if (entry == null) return RedirectToAction("Error"); foreach (TestEntry e in testEntryList) { if (e.ID == entry.ID) { testEntryList.Remove(e); break; } } return RedirectToAction("List"); } [HttpPost] public ExamsAndAverages Index(string button, string newname, string score, string testNameItems) { ViewBag.Message = "Exams and Averages:"; if (button == "Add Exam" && newname != "") { testNameList.Add(newname); testEntryList.Add(new TestEntry(newname)); } if (button == "Add Score" && score != "" && testNameItems != "") for (int i = 0; i < testEntryList.Count; ++i) { if (testEntryList[i].Name == testNameItems) { testEntryList[i].Amount++; testEntryList[i].Sum += Convert.ToDouble(score); } } ViewBag.TestNameItems = new SelectList(testNameList); ViewBag.TestInfoItems = new SelectList(testEntryList); ViewBag.TestListSize = (testNameList.Count == 0) ? 1 : testNameList.Count; ModelState.Clear(); return View(); } } }