title: Modal plugin of Bootstrap 2 is not displayed by the center
body: <p>I use bootstrap modal plugin. But modal dialog is not shown in center.
  Why? my mistake?</p>
  
  <p><a href="http://dl.dropbox.com/u/573972/stackoverflow/bootstrap/modal.html">http://dl.dropbox.com/u/573972/stackoverflow/bootstrap/modal.html</a></p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;head&gt;
    &lt;meta charset="utf-8"&gt;
    &lt;title&gt;test&lt;/title&gt;
    &lt;meta name="description" content=""&gt;
    &lt;meta name="author" content=""&gt;
    &lt;!-- Mobile Specific--&gt;
    &lt;meta name="viewport" content="width=device-width, initial-scale=1.0"&gt;
    &lt;!-- CSS--&gt;
    &lt;link rel="stylesheet" href="bootstrap.min.css"&gt;
    &lt;script src='http://cdnjs.cloudflare.com/ajax/libs/jquery/1.7/jquery.min.js'&gt;&lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
    &lt;div id="login" class="modal"&gt;
      &lt;div class="modal-header"&gt;
        &lt;h3&gt;Login to Room fuga&lt;/h3&gt;
      &lt;/div&gt;
      &lt;div class="modal-body"&gt;
        hogehoge
      &lt;/div&gt;
    &lt;/div&gt;
    &lt;script src="bootstrap.min.js"&gt;
    &lt;/script&gt;
    &lt;script&gt;
  $('#login').modal();
  &lt;/script&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>