JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://ajax.microsoft.com/ajax/jquery.validate/1.7/jquery.validate.js"></script>
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.2/themes/ui-lightness/jquery-ui.css">
<div id='ListBox'>
    <input type='checkbox' /><label>a</label>
    <br>
    <input type='checkbox' /><label>b</label>
    <br>
    <input type='checkbox' /><label>c</label>
</div>
<br><br>
<input id="Selected" type='text' />

JavaScript

$(document).ready(function(){
    $("#ListBox input").click(function() {
        var cbText = $('#ListBox').find(':checked').next()
            .map(function() {
                return $.text([this]);
            }).get().join(', ');
        
        $('#Selected').val(cbText);    
    });
});