Print screen using Javascript

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>

html2canvas(document.body, {
onrendered: function(canvas) {
document.body.appendChild(canvas);
}
});

The above code will take the printscreen of the webpage.

For real time example: http://html2canvas.hertzen.com/examples.html