我想在我的下拉列表中使用select2。这是我的代码。但这是行不通的。我需要在.cs文件中写一些东西吗？

Question

<link href="Content/css/select2.min.css" rel="stylesheet" />
<script type="text/javascript">

    $(document).ready(function () {
        $("#<%=ddlCName.ClientID%>").select2({
            placeholder: "Choose One",
            allowClear: true

      });

  });

</script>

<div class="col-md-3">
    <asp:DropDownList ID="ddlCName" CssClass="form-control input-sm" runat="server" Height="33px" Width="250px" DataSourceID="SqlDataSource1" DataTextField="CName" DataValueField="CName">
    </asp:DropDownList>

    <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:MyConnection %>" SelectCommand="SELECT [CName] FROM [CustomerRegister] ORDER BY [CName]"></asp:SqlDataSource>
</div>