title: Why does BeginForm("Foo") add a "Length" key to the query string?
body: <p>I am not new to MVC so I am a bit baffled at why I can't change the URL of my POST when I click the submit button.</p>
  
  <p>I have this simple view called PandoraRemovalTool.cshtml</p>
  
  <pre><code>@{
      ViewBag.Title = "PandoraRemovalTool";
  }
  @using (Html.BeginForm("PandoraGetDocsList"))
  {
      &lt;h2&gt;Pandora Removal Tool&lt;/h2&gt;    
      @Html.Label("Member number:")
      @Html.TextBox("txtMemberNumber")
      &lt;br /&gt;
      &lt;input type="submit" value="Search"/&gt;
  }
  </code></pre>
  
  <p>Because of it's simplicity I am not using a model, I only want to POST the txt value. However the URL is a bit odd. It's pointing to this path in the site:</p>
  
  <pre><code>&lt;form action="/Administration/PandoraRemovalTool?Length=18" method="post" novalidate="novalidate"&gt;    
      &lt;h2&gt;Pandora Removal Tool&lt;/h2&gt;
      &lt;label for="Member_number:"&gt;Member number:&lt;/label&gt;
      &lt;input id="txtMemberNumber" name="txtMemberNumber" type="text" value=""/&gt;        
      &lt;br&gt;
      &lt;input type="submit" value="Search"/&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>I don't understand where it's getting length=18 from. I want to post to this method:</p>
  
  <pre><code>[HttpPost]
  public ActionResult PandoraGetDocsList(string txtMemberNumber)
  {
      return RedirectToAction("PandoraRemovalTotal2", new {MemberNum = txtMemberNumber });
  }
  
  public ActionResult PandoraRemovalTotal2(string MemberNum)
  {
      return View();
  }
  </code></pre>
  
  <p>Some help please?</p>