title: django filter_horizontal can't display
body: <p>Here is model:</p>
  
  <p><code>author=models.ManyToManyField(Author)</code></p>
  
  <p>modelAdmin:
  <code>filter_horizontal=("author",)</code></p>
  
  <p>It's still rendering a multiple select widget.
  I don't know what's the problem.</p>
  
  <p>Django 1.5.</p>
  
  <p>mysite/mysite/views.py</p>
  
  <pre><code>from django.shortcuts import render_to_response
  from django.http import HttpResponse,Http404
  import datetime
  
  def hello(request):
      return HttpResponse("Hello world")
  
  def current_time(request):
      now=datetime.datetime.now()
      return render_to_response('current_datetime.html',{'current_date':now})#(template,context) ADDED BY ROBERT
  
  def hours_ahead(request,offset):
      try:
      offset=int(offset)
      except ValueError:
      raise Http404()
      dt=datetime.datetime.now()+datetime.timedelta(hours=offset)
      html='In %d hours, it will be %s.'%(offset,dt)
      return HttpResponse(html)
  
  def display_meta(request):
      values=request.META.items()
      values.sort()
      html=[]
      for k,v in values:
      html.append('&lt;tr&gt;&lt;td&gt;%s&lt;/td&gt;&lt;td&gt;%s&lt;/td&gt;&lt;/tr&gt;'%(k,v))
      return HttpResponse('&lt;table&gt;%s&lt;/table&gt;' % '\n'.join(html))
  </code></pre>
  
  <p>mysite/mysite/urls.py</p>
  
  <pre><code>from django.conf.urls import patterns, include, url
  from mysite.views import *
  #from books import views
  from books import views
  
  # Uncomment the next two lines to enable the admin:
  from django.contrib import admin
  admin.autodiscover()
  
  urlpatterns = patterns('',
      ('^hello/$',hello),
      ('^time/$',current_time),
      (r'^time/(\d{1,2})/$',hours_ahead),
      (r'^admin/',include(admin.site.urls)),
      (r'^display_meta/$',display_meta),
      (r'^search/$',views.search),
  )
  </code></pre>
  
  <p>mysite/books/models.py</p>
  
  <pre><code>from django.db import models
  from django.contrib import admin
  
  # Create your models here.
  
  class Publisher(models.Model):
      name=models.CharField(max_length=30)
      address=models.CharField(max_length=50)
      city=models.CharField(max_length=60)
      state_province=models.CharField(max_length=30)
      country=models.CharField(max_length=30)
      website=models.URLField()
  
      def __unicode__(self):
      return self.name
  
  class Author(models.Model):
      first_name=models.CharField(max_length=30)
      last_name=models.CharField(max_length=30)
      email=models.EmailField(blank=True,verbose_name='e-mail')
      def __unicode__(self):
      return u'%s %s' %(self.first_name,self.last_name)
  
  class AuthorAdmin(admin.ModelAdmin):
      list_display=('first_name','last_name','email')
      search_fields=('first_name','last_name')
  
  class Book(models.Model):
      name=models.CharField(max_length=100)
      author=models.ManyToManyField(Author)
      publisher=models.ForeignKey(Publisher)
      publication_date=models.DateField(null=True,blank=True,verbose_name='Publication Date')
      def __unicode__(self):
      return u'%s' % self.name
  
  class BookAdmin(admin.ModelAdmin):
      list_display=('name','publisher','publication_date')
      list_filter=('publication_date',)
      ordering=('-publication_date',)
      date_hierachy='publication_date'
  #fields=('name','author','publisher','publication_date')
      filter_horizontal=('author',)
  </code></pre>
  
  <p>admin.py</p>
  
  <pre><code>from django.contrib import admin
  from books.models import *
  
  admin.site.register(Publisher)
  admin.site.register(Author,AuthorAdmin)
  admin.site.register(Book,BookAdmin)
  </code></pre>