title: Select a valid choice.[<selection>]is not one of the available choices. Error
body: <p>What I want is multi-selected anwsers chosen to be saved and submitted to DB</p>
  
  <p>However I get this error on each of the questions.</p>
  
  <p><strong>my models.py</strong></p>
  
  <pre><code>class preferences(models.Model):
      cuisine = (
          (1,u'Italian'),
          (2,u'American'),
          (3,u'French'),
          (4,u'Japanese'),
          (5,u'Russian'),
          (6,u'Chinese'),
          (7,u'Mexican'),
          (8,u'Indian'),
          (9,u'Middle Eastern'),
          (10,u'Thai'),
          (11,u'Spanish')
      )
      vegeterian = (
          (1,u'Yes'),
          (2,u'No'),
          (3,u'I appreciate both')
      )
      lunch = (
          (1,u'Cafe'),
          (2,u'Restaurant'),
          (3,u'Fast Food'),
          (4,u'Takeaway'),
          (5,u'Grocery/Lunch Box')
      )
      dinner = (
          (1,u'Inexpensive Restaurant'),
          (2,u'Fine Dining'),
          (3,u'Takeaway'),
          (4,u'Fast Food'),
          (5,u'Delivery'),
          (6,u'Cooking at home'),
          (7,u'Cheeky Bar') #Make it with a hint that having a dinner w/ a cheeky pint
  
      )
      Friday = (
          (1,u'Bar'),
          (2,u'Night club'),
          (3,u'Karaoke'),
          (4,u'Netflix &amp; chill'),
          (5,u'Video games'),
          (6,u'Cinema'),
          (7,u'Theater'),
          (8,u'Restaurant'),
      )
  
      weekend = (
          (1,u'Hiking'),
          (2,u'Sport activities'),
          (3,u'Attending sport events'),
          (4,u'Music events'),
          (5,u'Art/Science exhibitions'),
          (6,u'Chilling at the park'),
          (7,u'Video games'),
          (8,u'Cinema'),
          (9,u'Theater'),
          (10,u'Chilling at home')
      )
  
      UserID = models.ForeignKey(User,related_name='User', null=True,default='')
      cuisine = models.ManyToManyField('self',choices=cuisine, max_length=20,blank=False,default='')
      cuisine_extra = models.CharField(max_length=25)
      vegeterian = models.CharField(max_length=15,choices=vegeterian)
      lunch = models.ManyToManyField('self',choices=lunch,max_length=20,blank=False,default='')
      dinner = models.ManyToManyField('self',choices=dinner,max_length=20,blank=False,default='')
      Friday = models.ManyToManyField('self',choices=Friday,max_length=20,blank=False,default='')
      weekend = models.ManyToManyField('self',choices=weekend,max_length=40,blank=False,default='')
  </code></pre>
  
  <p>Here I use <code>M2Mfield</code> as we are storing multiple items and use it on the same <code>model('self')</code>.</p>
  
  <p><strong>modelform.py</strong></p>
  
  <pre><code>class preferencesForm(ModelForm):
  
      """def __init__(self, *args, **kwargs):
          super(preferencesForm, self).__init__(*args, **kwargs)"""
  
  
      class Meta:
          model = preferences
          fields = ['cuisine', 'cuisine_extra', 'vegeterian', 'lunch', 'dinner', 'Friday', 'weekend']
          widgets = {
              'cuisine':forms.widgets.CheckboxSelectMultiple,
              'lunch':forms.widgets.CheckboxSelectMultiple,
              'dinner':forms.widgets.CheckboxSelectMultiple,
              'Friday':forms.widgets.CheckboxSelectMultiple,
              'weekend':forms.widgets.CheckboxSelectMultiple,
          }
  
  form = preferencesForm()
  </code></pre>
  
  <p>I tried doing it with <code>__init__</code>, that didn't help either. and at this point I was lost.</p>
  
  <p><strong>views.py</strong> </p>
  
  <pre><code>def display_form(request):
      if not request.user.is_authenticated:
          return redirect(settings.LOGIN_URL)
      if request.method == 'POST':
          form = preferencesForm(request.POST)
          if form.is_valid():
              form.UserID = request.user
              form.save()
              return HttpResponseRedirect('/')
      else:
          form = preferencesForm()
      return render(request,'display.html',{'form':form})
  </code></pre>
  
  <p><strong>views.py</strong> should be fine, but just in case.</p>
  
  <p>The error looks like this</p>
  
  <blockquote>
    <p>Select a valid choice. [u'3', u'9'] is not one of the available
    choices.</p>
  </blockquote>
  
  <p>(the selection depends on the number of a selected choice, but the idea is the same)
  I also tried changing integers to a string, didnt help either.
  Also tried <code>[u'1']</code> etc, didn't work either.</p>
  
  <p>I know I can use a <strong>multiselectfield</strong> library, but that would be bad for my database, since storing multiple instances is not a very good idea.
  I have seen that there are quite a few similar errors, but none of them helped me :/
  Would greatly appreciate your help! Thanks!</p>
  
  <p>The error <a href="https://i.stack.imgur.com/kJScx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kJScx.png" alt="error"></a></p>