title: enable/disable div on click
body: <p>I want to enable an overlay <code>div</code> on click and disable it when it is clicked on.</p>
  
  <p>Right now my code looks like this. Maybe the <code>.on .off</code> is used inappropriately?</p>
  
  <pre><code>$(function() {
      $("#sec_a_div").on("click","#wrapper_overlay");
  
  
      var docHeight = $(document).height();
  
      $("#wrapper_overlay")
        .height(docHeight)
        .css({
           'opacity' : 0.4,
           'position': 'absolute',
           'top': 0,
           'left': 0,
           'background-color': '#666666',
           'width': '100%',
           'z-index': 100
        })
  
      $.off("click","#wrapper_overlay");
  
  });
  </code></pre>