title: How to autofill fields in django
body: <p>i hope you can help me with this, i've been trying to make a form that autofills a field using the concatenation of two fields on the same form, but with no success, this is my model and my form</p>
  
  <pre><code>class Doctor(models.Model):
      name_doctor = models.CharField(max_length=20)
      last_doctor = models.CharField(max_length=20)
      email_doctor = models.EmailField()
      p_doctor = models.CharField(max_length=10)
      id_doctor = models.CharField(max_length=30, blank=True)
  
      def __str__(self):
          return '%s %s' % (self.name_doctor, self.last_doctor)
  </code></pre>
  
  <p>And my form:</p>
  
  <pre><code>class ADoctor(forms.ModelForm):
      class Meta:
          model = Doctor
          fields = ('name_doctor', 'last_doctor', 'email_doctor', 'p_doctor', 'id_doctor')
          labels = {
              'name_doctor': ('Name'),
              'last_doctor': ('Last name'),
              'email_doctor': ('Email'),
              'p_doctor': ('Phone'),
              'id_doctor': ('ID'),
          }
  </code></pre>
  
  <p>How can i override the save so that when i send the form the field id_doctor fills with the concatenation of name_doctor + last_doctor ?</p>