title: Django Forms BooleanField on submit returns 'on'
body: <p>Hello I am new to Django Forms. I am trying to add a checkbox in my form. When I submit the form I am expecting the checkbox field should return True or False, (depending on wheter or not the checkbox is checked).</p>
  
  <p>But it is posting 'on' if the field is checked and posts nothing if the field is not checked.
  Following is code snippet from my form:</p>
  
  <pre><code>from django import forms
  class MyForm(forms.Form):
      def __init__(self):
          self.fields['has_code']= forms.CharField(widget= forms.CheckboxInput())
  </code></pre>
  
  <p>What I want is when I post the form, I should get Post data as {'has_code': True}</p>