如何使用javascript访问tabcontainer中的服务器控件

Question

我无法使用javascript访问选项卡容器中的Server Control 这是javascript函数。我做错了。

function SklPop()
{     
    var BtnAddSkl = document.getElementById("<%= BtnAddSkl.ClientID%>");
    var DdlSklPop = document.getElementById("<%= DdlSklPop.ClientID%>");
    BtnSklShowstyle.display = "none";
    DdlSklPop.selectedIndex = 0;
}




<asp:TabPanel ID="TbSkCr" runat="server" HeaderText="SkillNCertification">
        <HeaderTemplate>SkillNCertificates</HeaderTemplate>
        <ContentTemplate>
            </asp:UpdatePanel>
                        <input id="BtnAddSkl" type="button" value="Add" onclick="SklPop()" />
                <asp:UpdatePanel ID="UpSklPopDetails" runat="server" style="display: none">
                    <ContentTemplate>
                        <table id="TbSklPop">
                            <tr>
                                <td>
                                    <asp:Label ID="Label1" runat="server" Text="Skills"></asp:Label></td>
                                <td>
                                    <asp:DropDownList ID="DdlSklPop" runat="server"></asp:DropDownList></td>
                            </tr>
                        </table>
                    </ContentTemplate>
                </asp:UpdatePanel>

        </ContentTemplate>
    </asp:TabPanel>