居中的Div

    <div class="divWindow" style="text-align: center; position: absolute;
        left: 180px; width: 570px;" runat ="server" id ="DivRvc" visible ="false">
        <div style="text-align: left; padding: 25px;">
            <asp:Repeater runat="server" ID="repeaterRVC">
                <ItemTemplate>
                    <table>
                        <tr>
                            <td align="center">
                                <asp:ImageButton runat="server" ID="imgbtnRvc" OnCommand="imgBtnRvcClick" CommandName="imgbtnRvc"
                                    ImageUrl="~/admin/Images/RVC.gif" CommandArgument='<%#DataBinder.Eval(Container.DataItem, "Value")%>' /><br />
                                <asp:Label runat="server" ID="lblRvc" Text='<%#DataBinder.Eval(Container.DataItem, "Key")%>'></asp:Label>
                            </td>
                        </tr>
                    </table>
                </ItemTemplate>
            </asp:Repeater>
        </div>
        <br />
         <asp:Button runat="server" ID="btnCancel" Text="取消" CssClass="inputbutton" OnClick="btnBack_Click" />
    </div>