Required Field Validator not working for JQuery chosen drop down list

Question

I am using JQuery Choosen for my DropDownList but the required validator for that dropdown is not working . Following is my code .Please guide where i am wrong.

Chosen plugin included in the form

 $(".chosen-select").chosen();

DropDownList code

<li>
    @Html.LabelFor(m => m.DepartmentId)
    @Html.DropDownListFor(x => x.DepartmentId, (ViewBag.DepartmentsList) as IEnumerable<SelectListItem>, "-- Select an Option --",new { @class = "chosen-select", @style = "width:312px; height:31px;" })
    @Html.ValidationMessageFor(m => m.DepartmentId)
</li>

And Model for the DropDownList

[Required(ErrorMessage = "*")]
[Display(Name = "Department Name")]
public int DepartmentId { get; set; }

Answer 1

jQuery Chosen updates the html by making the original select hidden (style="Display:none"). By default jquery.validate (1.9.0) ignores hidden elements. You can override the default using

$.validator.setDefaults({ 
  ignore: []
});