var items = new Array();
items[0] = "http://www.publicdomainpictures.net/pictures/10000/nahled/abstract-orange-background-29541280675430Trj9.jpg";
items[1] = "http://www.psdgraphics.com/wp-content/uploads/2011/03/red-flowing-background.jpg";
items[2] = "http://www.dvd-ppt-slideshow.com/images/ppt-background/background-3.jpg";
items[3] = "http://www.purplebackgrounds.net/wp-content/uploads/2011/10/purple-heart-background-680x544.jpg";
items[4] = "http://www.freeppt.net/background/beautiful-on-green-backgrounds-for-powerpoint.jpg";

$(function() {
    var bg_img = '',
        last_bg = '';
    $("a").click(function() {
        bg_img = items[Math.floor(Math.random() * items.length)];
        if (last_bg == bg_img) bg_img = items[Math.floor(Math.random() * items.length)];
        last_bg = bg_img;
        $("body").css('backgroundImage', 'url(' + bg_img + ')');
    });
});

Setting Validate Copy Format

body{
  background:url("http://www.freeppt.net/background/modern-pink-floral-backgrounds-for-powerpoint.jpg");
}

Setting Validate Copy Format

<div>
  <p>
    When you click on following paragraph link, every time it will be changed random background of the page
  </p>
  
  <p>
    You have a present that was really memorable. It could have been given for an 
    <a href="#">
      important occasion
    </a>
    or just for no reason at all. Tell us about the present and why it was memorable. Include the reason it was given, a 
    <a href="#">
      description
    </a>
    of it, and how you felt when you got it.
    
    The objective is to write a 
    <a href="#">
      narrative essay
    </a>
    about this present you were given
    
    The subject is a 
    <a href="#">
      memorable present
    </a>
    The three main subtopics are:
    <ul>
      <li>
        <a href="#">
          the reason it was given
        </a>
      </li>
      <li>
        <a href="#">
          a description of it and
        </a>
      </li>
      <li>
        <a href="#">
          how you felt when you got it
        </a>
      </li>
  </ul>
</p>
</div>

Copy Format

Download