title: Check if element exists within DIV
body: <p>I want to, on click, move an element inside a div unless it's already inside it. I was thinking something like...</p>
  
  <p>Click tag > If element is in div do nothing > Else move element into div</p>
  
  <p><a href="http://jsfiddle.net/establish/Xhhe8/" rel="noreferrer">http://jsfiddle.net/establish/Xhhe8/</a></p>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;ul&gt;
    &lt;li&gt;&lt;a href="#" class="tag"&gt;Art&lt;/a&gt;&lt;/li&gt;
    &lt;li&gt;&lt;a href="#" class="tag"&gt;Computing&lt;/a&gt;&lt;/li&gt;
    &lt;li&gt;&lt;a href="#" class="tag"&gt;Design&lt;/a&gt;&lt;/li&gt;
  &lt;/ul&gt;
  
  &lt;div id="crate"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p><strong>jQuery</strong></p>
  
  <pre><code>$('.tag').on('click', function(event) {
  
  if ($('#crate').has(this)) {
      // do nothing
  }
  
  else {
  
      $(this).appendTo('#crate');
  }
  });
  </code></pre>
  
  <p>It doesn't work. Also not sure how to represent 'do nothing', usually I just use a singular IF statement so no need to represent it. Can I do this to 'do nothing' and disable the click?</p>
  
  <pre><code>$(this).off(); 
  </code></pre>