def ignore_fields(model, field_names=[]):
    """
        Returns a list containing all field-names of a form, except 
        for the field-names in field_names. Use with form_for_*.
    """
    ret = []
    for field in model._meta.fields + model._meta.many_to_many:
        if not (field.name in field_names):
            ret.append(field.name)
    return ret