title: How to choose the value and label from Django ModelChoiceField queryset
body: <p>I was trying to create a django form and one of my field contain a ModelChoiceField </p>
  
  <pre><code>class FooForm(forms.Form):
  
      person =  forms.ModelChoiceField(queryset=Person.objects.filter(is_active=True).order_by('id'), required=False)
      age = forms.IntegerField(min_value=18, max_value=99, required=False)
  </code></pre>
  
  <p>When I try the code above what it return as an html ouput is</p>
  
  <pre><code>&lt;option value="1"&gt;Person object&lt;/option&gt;
  </code></pre>
  
  <p>on my Person Model I have the fields "id, fname, lname, is_active" . Is it possible to specify that my dropdown option will use "id" as the value and "lname" as the label? The expected html
  should be</p>
  
  <pre><code>&lt;option value="1"&gt;My Last Name&lt;/option&gt;
  </code></pre>
  
  <p>Thanks in advance!</p>