Print Java Script and Button

<script type="text/javascript">
        function printContent(el) {
            var restorepage = document.body.innerHTML;
            var printcontent = document.getElementById(el).innerHTML;
            document.body.innerHTML = printcontent;
            window.print();
            document.body.innerHTML = restorepage;
        }
    </script>
 <div id="div1" class="block">
       some text..............
</div>
  <button class="btn btn-success" type="button" onclick="printContent('div1')" style="width: 60px;">
        Print
    </button>