title: jQuery: change a css value if a option is selected
body: <p>I'm trying to make an option dropdown menu and I got stuck when I try to show a textbox if the option 'other' is selected.</p>
  
  <p>there's what I have:</p>
  
  <pre><code>&lt;span id="con-country"&gt;&lt;label for="country"&gt;Country: &lt;/label&gt;
  &lt;select name="country" required="required"&gt;
  &lt;option value="usa"&gt;United States&lt;/option&gt;
  &lt;option value="uk"&gt;United Kingdom&lt;/option&gt;
  &lt;option id="other" value="other"&gt;Other&lt;/option&gt;
  &lt;/select&gt;
  &lt;/span&gt;
  
  &lt;span id="con-specify"&gt;
  &lt;label for="specify"&gt;Specify: &lt;/label&gt;
  &lt;input type="text" name="specify" id="c-specify" required="required"&gt;&lt;/input&gt;
  &lt;/span&gt;
  </code></pre>
  
  <p>CSS:</p>
  
  <pre><code>#con-specify{
      margin-left: 50px;
      display: none;
  }
  </code></pre>
  
  <p>Simple huh?, the problem is that I don't know how to do the code in jQuery</p>
  
  <p>So, if the user select other in the menu, then the textbox should appear, how can I do that?</p>