title: How to have additional field besides the fields in the model in ModelForm
body: <p>I have a model named Customer and modelForm named Customer, but in my form i need more fields than the fields in Model. For example i want a confPass field in my ModelForm.
  Code for Model:</p>
  
  <pre><code>class Customer(models.Model):
      name = models.CharField(max_length=50)
      email = models.EmailField(max_length=100, unique=True)
      mobile_no = models.CharField(unique=True, validators=[validate_mobile], max_length=10)
      state = models.CharField(choices=STATES, max_length=2)
      city = models.CharField(max_length=20)
      password = models.CharField(max_length=256)
  
      def __str__(self):
          return self.email
  
  
  class CustomerForm(ModelForm):
      class Meta:
          model = Customer
          fields = ['name', 'email', 'mobile_no', 'state', 'city', 'password']
  
      def __init__(self, *args, **kwargs):
          super().__init__(*args, **kwargs)
          self.fields['name'].widget.attrs.update({'placeholder': 'Enter Name', 'class': 'form-control'})
          self.fields['email'].widget.attrs.update({'placeholder': 'Enter Email', 'class': 'form-control'})
          self.fields['mobile_no'].widget.attrs.update({'placeholder': 'Enter Mobile Number   ', 'class': 'form-control'})
          self.fields['state'].widget.attrs.update({'class': 'form-control'})
          self.fields['city'].widget.attrs.update({'placeholder': 'Enter City', 'class': 'form-control'})
          self.fields['password'].widget.attrs.update({'class': 'form-control'})
  </code></pre>