I have a problem in customizing labels in a Django form

This is the form code in file contact_form.py:

from django import forms

class ContactForm(forms.Form):
    def __init__(self, subject_label="Subject", message_label="Message", email_label="Your email", cc_myself_label="Cc myself", *args, **kwargs):
    super(ContactForm, self).__init__(*args, **kwargs)

        self.fields['subject'].label = subject_label
        self.fields['message'].label = message_label
        self.fields['email'].label = email_label
        self.fields['cc_myself'].label = cc_myself_label

    subject = forms.CharField(widget=forms.TextInput(attrs={'size':'60'}))
    message = forms.CharField(widget=forms.Textarea(attrs={'rows':15, 'cols':80}))
    email = forms.EmailField(widget=forms.TextInput(attrs={'size':'60'}))
    cc_myself = forms.BooleanField(required=False)

The view I am using this in looks like:

def contact(request, product_id=None):
    .
    .
    .
    if request.method == 'POST':
        form = contact_form.ContactForm(request.POST)
        if form.is_valid():
            .
            .
        else:
            form = contact_form.ContactForm(
                subject_label = "Subject",
                message_label = "Your Message",
                email_label = "Your email",
                cc_myself_label = "Cc myself")

The strings used for initializing the labels will eventually be strings dependent on the language, i.e. English, Dutch, French etc.

When I test the form the email is not sent and instead of the redirect-page the form returns with:

<QueryDict: {u'cc_myself': [u'on'], u'message': [u'message body'],
u'email':[u'[email protected]'], u'subject': [u'test message']}>:

where the subject label was before. This is obviously a dictionary representing the form fields and their contents.

When I change the file contact_form.py into:

from django import forms

class ContactForm(forms.Form):
    """
    def __init__(self, subject_label="Subject", message_label="Message", email_label="Your email", cc_myself_label="Cc myself", *args, **kwargs):
    super(ContactForm, self).__init__(*args, **kwargs)

        self.fields['subject'].label = subject_label
        self.fields['message'].label = message_label
        self.fields['email'].label = email_label
        self.fields['cc_myself'].label = cc_myself_label
    """
    subject = forms.CharField(widget=forms.TextInput(attrs={'size':'60'}))
    message = forms.CharField(widget=forms.Textarea(attrs={'rows':15, 'cols':80}))
    email = forms.EmailField(widget=forms.TextInput(attrs={'size':'60'}))
    cc_myself = forms.BooleanField(required=False)

i.e. disabling the initialization then everything works. The form data is sent by email and the redirect page shows up. So obviously something the the init code isn't right. But what?

I would really appreciate some help.