title: show feedback only when asked
body: <p>I'm creating a feedback. I show the success message when it's good and error when there is something wrong, but my css (red and green block) is there from the beginning. How can I hide this before there is feedback?</p>
  
  <pre><code>&lt;div id="feedback_success"&gt;
      &lt;?php if(empty($feedback_success)) { ?&gt;
          &lt;h1 &gt;&lt;/h1&gt;
      &lt;?php } else { ?&gt;
          &lt;h1&gt;&lt;?php echo $feedback_success ?&gt;&lt;/h1&gt;
      &lt;?php } ?&gt;
  &lt;/div&gt;
  &lt;div id="feedback_error"&gt;
      &lt;?php if(empty($feedback_error)) { ?&gt;
          &lt;h1 &gt;&lt;/h1&gt;
      &lt;?php } else { ?&gt;
          &lt;h1&gt;&lt;?php echo $feedback_error ?&gt;&lt;/h1&gt;
      &lt;?php } ?&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>css</p>
  
  <pre><code>#feedback_success
  {
      background-color: #45e589;
      color: white;
      padding:10px;
      font-size:1.0em;
  }
  
  
  #feedback_error
  {
      background-color: #ff5555;
      color: white;
      padding:10px;
      font-size:1.2em;
  }
  </code></pre>