title: Console Error with Ajax: ReferenceError: $ is not defined
body: <p>i have a problem with a little script on my html page. It's just a function which should be called by an onclick method in an a tag. It dont works. Everytime i click on the link in the browser the console says "ReferenceError: $ is not defined" and points on the third line of the code below.</p>
  
  <pre><code>&lt;script&gt;
      function del(urlToDelete) {
          $.ajax({
              url: urlToDelete,
              type: 'DELETE',
              success: function(results) {
                  location.reload();
              }
          });
      }
  &lt;/script&gt;
  </code></pre>