Bootstrap Multiselect Skeleton

HTML

<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/css/bootstrap.css">
<link rel="stylesheet" href="http://davidstutz.github.io/bootstrap-multiselect/dist/css/bootstrap-multiselect.css">
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/js/bootstrap.js"></script>
<script src="http://davidstutz.github.io/bootstrap-multiselect/dist/js/bootstrap-multiselect.js"></script>
<select id="ddlPermission" multiple="multiple" name="permission_ddl">
  <option value="A">A</option>
  <option value="B">B</option>
  <option value="C">C</option>
  <option value="D">D</option>
</select>
<input type="submit" name="btnSubmit" id="btnSubmit" onclick="myFunction()" class="button active" value="Submit">

JavaScript

$(document).ready(function() {
  $('#ddlPermission').multiselect({
    buttonWidth : '100%',
    maxHeight : 100,
    includeSelectAllOption : true,
    dropRight : true
  });
});

function myFunction() {
  var allVal=$("#ddlPermission").val();
  alert(allVal);
  return false;
}