I have came up to the similar problem and tried to solve it with like this in forms.py:

def __init__( self, *args, **kwargs ):
product_categories = None
if ‘product_categories’ in kwargs:
product_categories = kwargs.pop( ‘product_categories’ )
super( NewProductForm, self ).__init__( *args, **kwargs )
if product_categories:
self.fields["product_category"].widget.choices = product_categories

…where product_category is something like:
product_category = forms.ChoiceField( choices = [], required = False, label = _( ‘Product category’ ), initial = ‘r’ )

I almost gave up and was thinking of “manually” creating forms , … and I really do not understand why this “thingy” did not work when I POSTed data, … but luckily I have found your solution.

Thank you.

Things I would do to debug the problem:
1) use a browser and try /ajax_load/number_here/ and see that I actually get the json response back
2) use firebug and look at the requests (if you’re not already doing that)
3) check that field ids match those you use in your javascript code
4) careful with character escaping (in your template you have a < instead of <) and finally
5) go to #django in freenode and ask as people there are really friendly and helpful

Hope that helps.

Maybe i’m doing something wrong:

1) i placed this inside urls.py
(r’^myview/$’, ‘Representantes.dynamic_choice.views.myview’),
(r’^ajax_load/(\d+)/$’, ‘Representantes.dynamic_choice.views.get_2ndCF_values_json’),

2) my template “myform.html” looks like this:
http://dpaste.com/hold/88658/

Thanks