How to save Particular HTML section as a PDF FIle?

Needed scripts:
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script type="text/javascript" src="jspdf.js"></script>
<script type="text/javascript" src="standard_fonts_metrics.js"></script> 
<script type="text/javascript" src="split_text_to_size.js"></script>               
<script type="text/javascript" src="from_html.js"></script>
<script type="text/javascript" src="filesaver.js"></script>

HTML Portion:

<div id="save_datas">
     <h3>This is My part of contents...</h3>
</div>

<div id="content">
     <h5>A Very good Morning to every one</h5>
    <div>Very Nice Environment...</div>
</div>
<div id="doc_area"></div>
<button id="cmd">save Contents as PDF</button>

JS SECTION:

<script type="text/javascript">
$(function () {
    var doc = new jsPDF();
    var specialElementHandlers = {
        '#doc_area': function (element, renderer) {
            return true;
        }
    };

    $('#cmd').click(function () {
        doc.fromHTML($('#save_datas').html(), 15, 15, {
            'width': 170,
                'elementHandlers': specialElementHandlers
        });
        doc.save('myfile.pdf');
    });
});
</script>