<script src="http://code.jquery.com/jquery-1.11.0.min.js"></script>
    <script>
        var work = $('body');

        var backgroundUrls = [
            'img/contentbackground1.jpg',
            'img/contentbackground2.jpg',
            'img/contentbackground3.jpg',
            'img/contentbackground4.jpg'
        ];

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