title: Show new field after button click
body: <p>I want to make a field that only shows up after a button click.<br>
  Heres my code so far:</p>
  
  <pre><code>            &lt;div class="control-group" style="display:none" id="passwordfield"&gt;
                  &lt;label class="control-label"&gt;Password:&lt;/label&gt;
  
                  &lt;div class="controls"&gt;&lt;input id="pw" type="password"&gt;&lt;/div&gt;
              &lt;/div&gt;
  </code></pre>
  
  <p>The "display:none" makes it invisible, after that I have my button and a javascript which should change the display to "block", thus making it visible again.</p>
  
  <pre><code>            &lt;div style="padding-left: 160px;padding-bottom:20px"&gt;
                  &lt;button class="btn btn-primary" onclick="showPWField()"&gt;Log-In&lt;/button&gt;
                  &lt;script&gt;
                      function showPWField() {
                          document.getElementByID("passwordfield").style.display = "block";
                      }
                  &lt;/script&gt;
              &lt;/div&gt;
  </code></pre>
  
  <p>But it just doesnt work. The function gets called I tested that with an alert, but I just can't change the style :/</p>
  
  <p>Thanks for help in advance</p>