title: Change size of fields in Admin
body: <p>How can you change the size of a form field?</p>
  
  <p>For example, see the following code:</p>
  
  <pre><code>class MyModelAdmin(admin.ModelAdmin):
    def formfield_for_dbfield(self, db_field, **kwargs):
      field = super(ContentAdmin, delf).formfield_for_dbfield(db_field, **kwargs)
      if db_field.name == 'somefield':
        field.widget.attrs['class'] = 'someclass ' + field.widget.attrs.get('class', '')
      return field
  </code></pre>
  
  <p>but when I use this I get ContentAdmin unknown, how do I do this?</p>