求高手:net_lover? 不能垂直居中!100分哦!

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Untitled Page</title>
    <style>
    html,body,form,table,div{height:100%}
    </style>
</head>
<body style="background-color:Blue;">
    <form id="form1" runat="server">
        <div>
        <table cellspacing="0" cellpadding="0" border="0">
            <tbody>
                <tr>
                    <td style="width: 9px; vertical-align: middle; text-align: center;">
                        <img id="image1Id" src="images/left.gif"  onclick="changeState();"  alt="关闭/打开左栏"  border="0" />
                    </td>
                </tr>
            </tbody>
        </table>
        </div>
    </form>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">