Print MS Chart in ASP.Net

<script type="text/javascript">
<!--
function printchart(elementId)
{
 var printContent = document.getElementById(elementId);
 var windowUrl = 'about:blank';
 var uniqueName = new Date();
 var windowName = 'Print' + uniqueName.getTime();
 var printWindow = window.open(windowUrl, windowName, 'left=50000,top=50000,width=0,height=0');

 printWindow.document.write(printContent.innerHTML);
 printWindow.document.close();
 printWindow.focus();
 printWindow.print();
 printWindow.close();
}
// -->
</script>