how to print a div or table in asp.net with back ground

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <link href="styles.css" rel="stylesheet" type="text/css" />

    <script language="javascript" type="text/javascript">

function getPrint(print_area)

{


if(confirm("Are you sure, you want to print?"))

{

var printContent = document.getElementById(print_area);


var printWindow = window.open('', '', 'left=50000,top=50000,width=0,height=0');

printWindow.document.write('<link rel="stylesheet" type="text/css" href="styles.css" />');

printWindow.document.write(printContent.innerHTML);


printWindow.document.close();

printWindow.focus();

printWindow.print();

printWindow.close();

}

}

    </script>

    <%--<style type="text/css">
  .myDiv
{
    background-image: url(./img/booked.gif);
  background-repeat:no-repeat;
}
</style>--%>
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div id="divSchool">
        <asp:Panel runat="server" ID="pnldiv" CssClass="myDiv">
          
            <asp:Label ID="lblroom" runat="server" Font-Bold="true" Text="print a div in asp.net"></asp:Label>
            <asp:Image ID="Image1" runat="server" ImageUrl="~/img/Einstein_1_JPEG.jpg.jpg" Width="100px" />
        </asp:Panel>
    </div>
    <asp:Button ID="ImageButton1" runat="server" Height="19px" Text="print" AlternateText="Print License"
        ToolTip="Print" OnClientClick="getPrint('divSchool')" Visible="true" />
    </form>
</body>
</html>