Return proper http status codes on delete

BL/Services/FoorumService.cs

@@ -30,11 +30,17 @@ namespace BL.Services
             throw new NotImplementedException();
         }
 
-        public void Delete(int id)
+        public FoorumDTO Delete(int id)
         {
             var f = _foorumRepository.GetById(id);
+            if (f == null)
+            {
+                return null;
+            }
             _foorumRepository.Delete(f);
             _foorumRepository.SaveChanges();
+
+            return _factory.Create(f);
         }
 
         public FoorumDTO Get(int id)
@@ -48,16 +54,22 @@ namespace BL.Services
             foreach (var f in _foorumRepository.GetAll())
             {
                 yield return _factory.Create(f);
-            }
-            
+            }   
         }
 
-        public void Hide(int id, bool hide=true)
+        public FoorumDTO Hide(int id, bool hide=true)
         {
             var f = _foorumRepository.GetById(id);
+            if (f == null)
+            {
+                return null;
+            }
+
             f.Visible = !hide;
             _foorumRepository.Update(f);
             _foorumRepository.SaveChanges();
+
+            return _factory.Create(f);
         }
 
         public IEnumerable<FoorumDTO> SearchFoorumAuthor(string query)