How to print a panel in SharePoint 2010

<Script type="text/javascript">

        function printform() {

            var printContent = document.getElementById("<%= pnlFullForm.ClientID %>");

            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>

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<input type="button" value="Print" id="btnPrint" title="Print" onclick="printform();"

                    class="ms-ButtonHeightWidth" />