title: Values don't change after posting back to view?
body: <p><em>Edit: I've changed my question and code to clarify my question better</em></p>
  
  <p>I've got this (strongly typed view) that does use the values provided in the controller for that specific model</p>
  
  <p>I want to add something to a Model from another model, after posting back from my httpPost action nothing happens...</p>
  
  <p>Thanks in advance!</p>
  
  <p>--------------------------------------other code to clarify my question a bit more----</p>
  
  <pre><code> public class Address
   {
  public int Id { get; set;}
  public String Name { get; set;}
   }
  
   public class OtherAddress
   {
  public int Id { get; set;}
  public String Name { get; set;}
  public String City { get; set;}
   }
  
   public class MasterModel
  {
   public Address Address { get; set;}
   public List&lt;OtherAddress&gt; OtherAddressess { get; set;}
   }
  
  
  
   public ActionResult Create()
   {
   MasterModel Model = new MasterModel();
   Model.Person = new Person();
   Model.Address = new Address();
   Model.OtherAdressess = new List&lt;OtherAddress&gt;();
  
   DBContext _db = new DBContext();
   Model.OtherAdressess = _db.OtherAddressess.Where(a=&gt; a.City == "Amsterdam");
   return View(Model);
   }
  </code></pre>
  
  <p>in the view</p>
  
  <pre><code>    @model Project.Models.MasterModel
  
      List&lt;SelectListItems&gt; items = new List&lt;SelectListItems&gt;();
  
      foreach(var a in Model.OtherAddressess)
      {
          SelectListItem item = new SelectListItem();
          item.Value = a.Id.toString();
          item.Text = a.Street;
      }
  
      @using (@Html.BeginForm())
      {
      &lt;div&gt;
      &lt;select name="otheraddress"&gt;
      foreach(var i in Items)
      {
          &lt;option value=@i.Value&gt;@i.Text&lt;/option&gt;
      }
      &lt;/select&gt;
      &lt;input type="submit" name="select" value="Select Address"/&gt;
      &lt;/div&gt;
      &lt;div&gt;
      @Html.EditorFor(model =&gt; Model.Address.Name)
      &lt;div&gt;
      &lt;p&gt;
      &lt;input type="submit" value="Submit"/&gt;
      &lt;/p&gt;
      }
  </code></pre>
  
  <p>in post</p>
  
  <pre><code>    [HttpPost]
      public ActionResult Create(MasterModel Model)
      {
      String otherAddressSelected = Request.Params["select"];
      if(!String.IsNullOrEmpty(otherAddressSelected))
      {
          int id = int.Parse(Request.Params["otheraddress"]);
          DBContext _db = new DBContext();
          OtherAddress oa = _db.OtherAddress.Single(oa=&gt; oa.Id == id);
          Model.Address.Name = oa.Name;
          return View(Model);
      }
      //other stuff here
      }
  </code></pre>