title: how can we do popup background disable when we click on anywhere in the relevent page
body: <p>i have a button when i click on it i show a popup with disable background but if  i click on anywhere in the page except popup it is not enabling</p>
  
  <pre><code>&lt;a href="#" onClick="pop('popDiv')"&gt;Click here to open a popup div&lt;/a&gt;
  
  &lt;a href="#" onClick="hide('popDiv')"&gt;Close&lt;/a&gt;
  
  &lt;script type="text/javascript"&gt;
  function pop(div) {
      document.getElementById(div).style.display = 'block';
  }
  function hide(div) {
      document.getElementById(div).style.display = 'none';
  }
  //To detect escape button
  document.onkeydown = function(evt) {
      evt = evt || window.event;
      if (evt.keyCode == 27) {
          hide('popDiv');
      }
  };
  &lt;/script&gt;
  </code></pre>