Admin now uses a custom form to sort User selection box

reddit/admin.py

@@ -1,5 +1,6 @@
 from django.contrib import admin
 from reddit.models import RedditAccount
+from reddit.forms import RedditAccountForm
 
 class RedditAccountAdmin(admin.ModelAdmin):
     list_display = ('username', 'user', 'date_created', 'link_karma', 'comment_karma', 'last_update')
@@ -7,6 +8,8 @@ class RedditAccountAdmin(admin.ModelAdmin):
 
     fields = ('user', 'username')
 
+    form = RedditAccountForm
+
     def save_model(self, request, obj, form, change):
         obj.api_update()
         obj.save()

reddit/forms.py

@@ -0,0 +1,16 @@
+from django import forms
+
+from django.contrib.auth.models import User
+from reddit.models import RedditAccount
+
+class RedditAccountForm(forms.ModelForm):
+    user = forms.ModelChoiceField(queryset=User.objects.order_by('username')) 
+    username = forms.CharField(label = u'Reddit Username', max_length=64)
+
+    def clean(self):
+        try:
+            eaccount = RedditAccount.objects.get(username=self.cleaned_data['username'])
+        except RedditAccount.DoesNotExist:
+            return self.cleaned_data
+        else:
+            raise forms.ValidationError("This User ID is already registered")