you insert the datalist in panel which name is
Panel1
Now you write this java script in this page.
<script language="JavaScript">
function printTable()
{
var printContent = document.getElementById("Panel1");
var windowUrl = 'about:blank';
var num;
var uniqueName = new Date();
var windowName = 'Print' + uniqueName.getTime();
var printWindow = window.open(num, windowName, 'left=50000,top=50000,width=0,height=0');
printWindow.document.write(printContent.innerHTML);
printWindow.document.close();
printWindow.focus();
printWindow.print();
printWindow.close();
}
</script>
you insert one html button and write this code
<input id="Button1" type="button" value="Print Bill" onclick="printTable()" />
i hope work.