I have a model that looks like this:

class Client(models.Model):
name = models.CharField(max_length=100, primary_key=True)
user = models.ForeignKey(User)       

class Contract(models.Model):                   
    title = models.CharField(max_length=100, primary_key=True)
    start_date = models.DateField()
    end_date = models.DateField()
    description = models.TextField()   
    client = models.ForeignKey(Client)  
    user = models.ForeignKey(User)     

How can i configure a django form so that only clients associated with that user show in the field in the form? My initial thought was this in my forms.py:

    client = forms.ModelChoiceField(queryset=Client.objects.filter(user__username = User.username))  

But it didn't work. So how else would I go about it?