title: Django: How to change the css id of a ModelMultipleChoiceField in a form?
body: <p>One of my forms is using a ModelMultipleChoiceField and it's showing a list of checkboxes on the html.</p>
  
  <pre><code>class CreateProfileForm(forms.Form):
      first_name = forms.CharField(label='First Name', max_length=50)
      last_name = forms.CharField(label='Last Name', max_length=50)
      topics = forms.ModelMultipleChoiceField(label='Assign Topic(s)', 
              widget=CheckboxSelectMultiple(),
              queryset=None)
  
      def __init__(self, *args, **kwargs):
          event = kwargs.pop('event')
          super (CreateProfileForm, self).__init__(*args, **kwargs)
          self.fields['topics'].queryset = Topic.objects.filter(event=event)
  </code></pre>
  
  <p>HTML output</p>
  
  <pre><code>&lt;div id="div_topics"&gt;
      &lt;label class="fields"&gt;
          &lt;strong&gt;&lt;label for="id_topics_0"&gt;Assign Topic(s)&lt;/label&gt;&lt;/strong&gt;
      &lt;/label&gt;
      &lt;ul&gt;
  &lt;li&gt;&lt;label for="id_topics_0"&gt;&lt;div class="checker" id="uniform-id_topics_0"&gt;&lt;span&gt;&lt;input type="checkbox" name="topics" value="3" id="id_topics_0" style="opacity: 0; "&gt;&lt;/span&gt;&lt;/div&gt; Size&lt;/label&gt;&lt;/li&gt;
  &lt;li&gt;&lt;label for="id_topics_1"&gt;&lt;div class="checker" id="uniform-id_topics_1"&gt;&lt;span&gt;&lt;input type="checkbox" name="topics" value="2" id="id_topics_1" style="opacity: 0; "&gt;&lt;/span&gt;&lt;/div&gt; Flavour&lt;/label&gt;&lt;/li&gt;
  &lt;li&gt;&lt;label for="id_topics_2"&gt;&lt;div class="checker" id="uniform-id_topics_2"&gt;&lt;span&gt;&lt;input type="checkbox" name="topics" value="1" id="id_topics_2" style="opacity: 0; "&gt;&lt;/span&gt;&lt;/div&gt; Citrus&lt;/label&gt;&lt;/li&gt;
  &lt;/ul&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>How can I change the value of the <code>id</code> of the <code>input type</code> element? Or basically change <code>id_topics_0</code> etc to something else?</p>