title: jQuery: Detect if element exists
body: <p>In my code I have the following html that gets appended to a List Item when the user clicks on a specific element.</p>
  
  <pre><code>&lt;span class="greenCheckMark"&gt;&lt;/span&gt;
  </code></pre>
  
  <p>Using jQuery, how would I detect if the element existed, and if so, not add another green checkmark?</p>
  
  <pre><code>$('.clickedElement').live('click',function(){
  //does the green check mark exist? if so then do nothing, else 
  $('#listItem).append('&lt;span class="greenCheckMark"&gt;&lt;/span&gt;');
  });
  </code></pre>