panel初始值为隐藏,点击button后无显示
详细问题：在gridview加panel，panel初始值为隐藏,点击button后显示,但点击button后没反应,估计是页面刷新了吧，所以又再次隐藏，那要怎样确保操作Panel里面的内容不会导致页面刷新？
部分代码：
<asp:GridView ID="gvMessage" runat="server" AutoGenerateColumns="False" 
                                Width="590px">
                                <Columns>
                                    <asp:TemplateField>
                                        <ItemTemplate>
                                            <table class="style5" bgcolor="White">
                                                <tr>
                                                    <td colspan="2">
                                                        作者：<asp:Label ID="lblUserName" runat="server" Text='<%# Bind("UserName") %>'></asp:Label>
                                                        于<asp:Label ID="lblCreateDate" runat="server" Text='<%# Bind("CreateDate") %>'></asp:Label>
                                                        留言！</td>
                                                </tr>