dashboard: if no more networks disabled the button

circle/dashboard/templates/dashboard/vm-detail/network.html

@@ -121,15 +121,15 @@
         {% csrf_token %}
         <div class="input-group" style="max-width: 330px;">
           <select name="new_network_vlan" class="form-control">
-            {% if vlans|length == 0 %} 
-              <option value="-1">No more networks!</option>
-            {% endif %}
             {% for v in vlans %}
               <option value="{{ v.pk }}">{{ v.name }}</option>
+              {% empty %}
+              <option value="-1">No more networks!</option>
             {% endfor %}
           </select>
           <div class="input-group-btn">
-            <button type="submit" class="btn btn-success"><i class="icon-plus-sign"></i></button>
+            <button {% if vlans|length == 0 %}disabled{% endif %}
+              type="submit" class="btn btn-success"><i class="icon-plus-sign"></i></button>
           </div>
         </div>
       </form>

circle/dashboard/views.py

@@ -400,7 +400,7 @@ class VmDetailView(CheckedDetailView):
         if not self.object.has_level(request.user, 'owner'):
             raise PermissionDenied()
 
-        vlan = Vlan.objects.get(pk=request.POST.get("new_network_vlan"))
+        vlan = get_object_or_404(Vlan, pk=request.POST.get("new_network_vlan"))
         if not vlan.has_level(request.user, 'user'):
             raise PermissionDenied()
         try: