1👍
you should try:
if request.method == 'POST':
form = ContactForm(request.POST)
mInstance = form.save(commit=False)
mInstance.trackerID = 23232;
mInstance.save()
Note the commit=False
parameter.
More info:
https://docs.djangoproject.com/en/1.6/topics/forms/modelforms/#the-save-method
Source:stackexchange.com