title: Overriding initial value in ModelForm
body: <p>in my Django (1.2) project, I want to prepopulate a field in a modelform, but my new value is ignored.
  This is the snippet:</p>
  
  <pre><code>class ArtefactForm(ModelForm):
      material = CharField(widget=AutoCompleteWidget('material', force_selection=False))
  
      def __init__(self, *args, **kwargs):
          super(ArtefactForm, self).__init__(*args, **kwargs)
          self.fields['material'].initial = 'Test'
  </code></pre>
  
  <p>I also tried with <code>self.base_fields</code>, but no effect: there is always the database-value displaying in the form. Any ideas?</p>