Initialize foreign key drop downs

Question

I want to populate two foreign key fields in one of my forms. The relevant bit of code is as below:

if request.method == 'POST':
    form = IssuesForm(request.POST or None)
    if request.method == 'POST' and form.is_valid():
        form.save()
else:
    form = IssuesForm(initial={'vehicle': stock_number, 'addedBy': request.user, })

vehicle points to the Vehicle class. addedBy is to contain the currently logged in user.

However the drop downs aren't initialized as I want...I still have to select the vehicle and user. From this I have two questions:

1. What could be the problem?
2. What is the best way to make these forms read-only?

EDIT 1 The IssueForm class looks like this so far:

class Issues(models.Model):
   vehicle = models.ForeignKey(Vehicle)
   description = models.CharField('Issue Description', max_length=30,)
   type = models.CharField(max_length=10, default='Other', choices=ISSUE_CHOICES)
   status = models.CharField(max_length=12, default='Pending', 
     choices=ISSUE_STATUS_CHOICES)
   priority = models.IntegerField(default='8', editable=False)
   addedBy = models.ForeignKey(User, related_name='added_by')
   assignedTo = models.CharField(max_length=30, default='Unassigned')
   dateTimeAdded = models.DateTimeField('Added On', default=datetime.today, 
     editable=False)
   def __unicode__(self):    
    return self.description

Form Class

class IssuesForm(ModelForm):   
  class Meta:
    model = Issues
    exclude = ('assignedTo')

Answer 1

For your second question, are you wanting to make the addedBy field read-only? If so, don't add it to your form (it'll never be read-only if you present it to the user, e.g. Firebug). You can instead populate it inside your save method.

if request.method == 'POST':
    form = IssuesForm(request.POST or None)
    if request.method == 'POST' and form.is_valid():
        issue = form.save(commit=False)
        issue.addedBy = request.user
        # any other read only data goes here
        issue.save()
else:
    form = IssuesForm(initial={'vehicle': stock_number}) # this is related to your first question, which I'm not sure about until seeing the form code