I am trying to use the ModelForm to add my data. It is working well, except that the ForeignKey dropdown list is showing all values and I only want it to display the values that a pertinent for the logged in user.

Here is my model for ExcludedDate, the record I want to add:

class ExcludedDate(models.Model):
date = models.DateTimeField()
reason = models.CharField(max_length=50)
user = models.ForeignKey(User)
category = models.ForeignKey(Category)
recurring = models.ForeignKey(RecurringExclusion)
def __unicode__(self):
    return self.reason

Here is the model for the category, which is the table containing the relationship that I'd like to limit by user:

class Category(models.Model):
name = models.CharField(max_length=50)
user = models.ForeignKey(User, unique=False)
def __unicode__(self):
    return self.name

And finally, the form code:

class ExcludedDateForm(ModelForm):
class Meta:
    model = models.ExcludedDate
    exclude = ('user', 'recurring',)

How do I get the form to display only the subset of categories where category.user equals the logged in user?