title: How do I keep field values in the ASP.NET MVC form if it has been invalidated?
body: <p>I have a form that is going through some validation before sending an e-mail.</p>
  
  <p>I have tried using this for validation, where the method ValidateInput sets the ModelState depending on the input:</p>
  
  <pre><code>[HttpPost]
  public ActionResult Create(FormCollection collection)
  {
      ValidateInput(collection);
      if (ModelState.IsValid == false) return View(collection);
  </code></pre>
  
  <p>This clears all the entered fields if something is invalid. I want to keep all the entered data in the field. How can I do that?</p>