def __init__(self, *args, **kwargs):
        "Sets custom meta data to the form's fields"
        super(ModelForm, self).__init__(*args, **kwargs)
        self.fields['title'].error_messages['required'] = _(
            "Please enter a class title")
        self.fields['description'].error_messages['required'] = _(
            "Please enter a class description")
        self.fields['max_students'].error_messages['required'] = _(
            "Please enter the maximum number of students in your class")