The handler in click button keeps adding everytime I refresh my page
<p>I use jquery to bind a click event in my link element and binding a handler. But every time I refresh the page the registration of the handler in my link element keeps adding. Like for example, in a new load page, only one handler registered in the click but when I click the link again, it it will add another handler.</p>

<p>Please advise.</p>

<p>Many thanks.</p>

<pre><code>$("#btn").click(function () {
  $("#blck").slideToggle("fast", function(){
  });
});
</code></pre>
