title: Multiple dropdownlists with different bound values getting overwritten
body: <p>I have an app with 3 dropdownlists that are all declared with razor synatx and use the same source list but with different bound values. All three are nullable values:</p>
  
  <pre><code>[Required]
  public int? PMDID1 { get; set; }
  public int? PMDID2 { get; set; }
  public int? PMDID3 { get; set; }
  </code></pre>
  
  <p>I get the list for the dropdownlist and save it to a session object and I've tried referencing the session object in the view itself, but right now I'm grabbing the value and adding it to the viewmodel so it's tightly bound.</p>
  
  <pre><code>var dlist = (List&lt;SelectListItem&gt;)Session["PDList"];
  eavm.DList = new List&lt;SelectListItem&gt;(dlist);
  return View(eavm);
  </code></pre>
  
  <p>and in the view:</p>
  
  <pre><code>@Html.DropDownListFor(m =&gt; m.Encounter.PMDID1, Model.DList, "", new { @class = "pvb-fieldBox" })
  @Html.DropDownListFor(m =&gt; m.Encounter.PMDID2, Model.DList, "", new { @class = "pvb-fieldBox" })
  @Html.DropDownListFor(m =&gt; m.Encounter.PMDID3, Model.DList, "", new { @class = "pvb-fieldBox" })
  </code></pre>
  
  <p>What's happening is when I load this page with a previous entry, where PMDID1 has a value, but 2 and 3 are null, it's populating all 3 dropdownlists with the selected value of PMDID1 despite the fact that the others are bound to 2/3. What can I do to ensure if they are null they just display the "" empty start value?</p>