Javascript 在ASP.net中使用dropdownlist打开现代弹出窗口

我有一个在asp.net中打开现代弹出窗口的代码，该代码运行良好。但我还想使用从deopdown列表中选择数据来打开弹出窗口。这是一个代码，我有赖特打开弹出窗口时，用户点击按钮，但我如何打开弹出窗口使用从下拉列表中选择项目，弹出显示升级会员资格

<asp:DropDownList ID="ddWeek" class="contact-input" runat="server" Width="400px"
        AutoPostBack="True" OnSelectedIndexChanged="ddWeek_SelectedIndexChanged">
            </asp:DropDownList>

      <div id="modal">
    <div id="headingpop2">
        Select You Plane for Upgrade Membership
    </div>
     <div id="contentpop2">
        <p>Select you plan as per you like to Upgrade</p>
        <a runat="server"  href="Becomeamember.aspx"
            class="buttonpop green close" style="margin-top: 140px; margin-right:     
       230px;">
            <img src="images/tick.png">Upgrade Now</a> <a style="margin-top: 140px; 
             margin-right: 50px;"
                href="#" class="buttonpop red close">
             <img src="images/cross.png">Cancel</a>
    </div>
</div>

<script type="text/javascript">
        $(document).ready(function () {
            $('#button1').click(function (e) { // Button which will activate our modal
                $('#modal').reveal({ // The item which will be opened with reveal
                    animation: 'fade',      // fade, fadeAndPop, none
                    animationspeed: 600,  // how fast animtions are
                    closeonbackgroundclick: true, // if you click background 
                     // will modal close?
                    dismissmodalclass: 'close' // the class of a button or 
                   //element that will close an open modal
                });
                return false;
            });
        });    
    </script>

这段代码是与按钮，但我希望它将与dropdownlist也工作。有人知道我该怎么做吗？请帮帮我

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谢谢

能否将类似的按钮处理程序附加到选择列表上的.change事件？我尝试了，但没有成功