Question

I have a code here using Loudev multiselect
I’m using a content page in C# and it’s not working properly for me.

Is there anything wrong with my code?

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
CodeFile="Default.aspx.cs" Inherits="_Default" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
<script src="Scripts/jquery.multi-select.js" type="text/javascript"></script>
<link href="Styles/multi-select.css" rel="stylesheet" type="text/css" />

<script type="text/javascript">
    $('#countries').multiSelect()
</script>


</asp:Content>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
<select multiple="multiple" id="countries" name="countries[]">

<option value="fr">France</option>
<option value="uk">United Kingdom</option>
  <option value="us">United States</option>
<option value="ch">China</option>
</select>

 </asp:Content>

Answer 1

First check, did you referenced jquery library file jquery.js in master page or not? If not then include it in master page or in default page before jquery.multi-select.js.

If you referenced correctly than change your code to

<script type="text/javascript">
    $(function(){
        $('#countries').multiSelect()
    });
</script>

Call multiselect when dom ready.

You are just selecting an element before it to load in dom.

Hope It will solve your issue.