title: Django raise ValidationError
body: <p>i have a problem with raise ValidationError, it won't display if the user writes only 1,2,3 words. If i press submit it shows only the title Contact and the submit button. It should show if user writes under 4 words.</p>
  
  <p>views.py</p>
  
  <pre><code>def contact(request):
      data = dict()
      if request.method == "POST":
          form = ContactForm(request.POST)
          if form.is_valid():
              subject = form.cleaned_data['subject']
              email = form.cleaned_data['email']
              message = form.cleaned_data['message']
              try:
                  send_mail(subject, message, email, ['inbox01@yahoo.com'])
              except BadHeaderError:
                  return HttpResponse('Invalid header found.')
              return HttpResponseRedirect('/contact/thanks/')
      else:
          data['form'] = ContactForm(
              initial={'subject': 'I love your site!'}
          )
  
      return render(request, 'contact_form.html', data)
  </code></pre>
  
  <p>forms.py</p>
  
  <pre><code>from django import forms
  
  
  class ContactForm(forms.Form):
      subject = forms.CharField(max_length=100)
      email = forms.EmailField(required=True)
      message = forms.CharField(widget=forms.Textarea, min_length=7)
  
      def clean_message(self):
          message = self.cleaned_data['message']
          num_words = len(message.split())
          if num_words &lt; 4:
              raise forms.ValidationError('Not enough words!')
          return message
  </code></pre>
  
  <p>contact_form.html</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang="en"&gt;
  &lt;head&gt;
      &lt;meta charset="UTF-8"&gt;
      &lt;title&gt;Contact us&lt;/title&gt;
  &lt;/head&gt;
  &lt;body&gt;
      &lt;h1&gt;Contact us&lt;/h1&gt;
  
      &lt;form action="" method="POST"&gt;
          &lt;table&gt;
              {{ form.as_table }}
          &lt;/table&gt;
          {% csrf_token %}
          &lt;input type="submit" value="Submit"&gt;
      &lt;/form&gt;
  
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>