def ShowSpecificEvent(request, eventslug):
event   = Event.objects.get(slug=eventslug)
form    = RemovalForm(request.POST or None)
context = {'event': event, 'form': form,}
if request.method == 'POST':
    if form.is_valid():
        updated_event = event.signed_up.remove(request.POST.get('for_removal'))
        updated_event.save()
        return HttpResponseRedirect('base_user_removed.html')
    else:
        return render_to_response('base_specific_event.html', context, context_instance=RequestContext(request))
return render_to_response('base_specific_event.html', context, context_instance=RequestContext(request))

signed_up       = models.ManyToManyField(User, related_name='signed_up', verbose_name='Already signed-up', blank=True, null=True)

class RemovalForm(forms.Form):
for_removal = forms.CharField(label='Username of attendee to be removed')

def clean_removalform(self):
    for_removal = self.cleaned_data['for_removal']

Traceback:

class RemovalForm(forms.Form):
    for_removal = forms.IntegerField(label='Userid of attendee to be removed')

    def clean_removalform(self):
       for_removal = self.cleaned_data['for_removal']

def ShowSpecificEvent(request, eventslug):
event   = Event.objects.get(slug=eventslug)
form    = RemovalForm(request.POST or None)
context = {'event': event, 'form': form,}
if request.method == 'POST':
    if form.is_valid():
        x = event.signed_up.get(username = form.cleaned_data['for_removal'],)
        event.signed_up.remove(x)
        event.save()
        return render_to_response('base_specific_event.html', context, context_instance=RequestContext(request))
    else:
        return render_to_response('base_specific_event.html', context, context_instance=RequestContext(request))
return render_to_response('base_specific_event.html', context, context_instance=RequestContext(request))