title: ASP.NET, TextBoxFor using JQuery MaskedInput not accepting input when others do
body: <p>I have a <code>@Html.TextBoxFor(...)</code> not accepting any input when I assign it a <code>.mask("(999) 999-999");</code> in a supporting JavaScript file, why?</p>
  
  <p>The textbox in question is located in <em>MainFocus.cshtml</em> with this HTML:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;div id="telephoneNumber" class="col-sm-3" style="width: 22% !important;"&gt;
      &lt;div&gt;
          &lt;label class="required"&gt;Telephone:&lt;/label&gt;
      &lt;/div&gt;
      &lt;div&gt;
          @Html.TextBoxFor(m =&gt; m.Telephone, new { id = "telephoneNumber", placeholder = "(xxx) xxx-xxxx", maxlength = "14" })
          @Html.ValidationMessageFor(m =&gt; m.Telephone)
      &lt;/div&gt;
      [...]
  &lt;/div&gt;
  </code></pre>
  
  <p>I then apply the mask in this Javascript file, <em>supportingScript.js</em>:</p>
  
  <pre class="lang-js prettyprint-override"><code>$("#telephoneNumber").mask("(999) 999-9999");
  </code></pre>
  
  <p>When I run the site, the masked textbox does not accept any input at all, despite the fact that other textboxes on the page that have also been masked the same way in <em>supportingScript.js</em> work just fine.</p>
  
  <p>Why is this?</p>