tabpages related

when I try to switch between the开发者_Go百科 tabs on Windows Form,it's not working one method. the first method is clearing comboBoxes and the second method is adding to the inside of combobox those datas from SQL the moral of the story,I'm adding a new data and then I can't see it within another comboboxes

if (tabAna.SelectedTab == tabFormGuncelle)
        {
            CombolariTemizle();
            BaglantiHazirla();
        }

if (tabAna.SelectedTab == tabFormOnayla)
       {
           CombolariTemizle();
           BaglantiHazirla();
       }

I can only see that both codepaths are identical, i.e. both if-bodies are exactly the same. Possibly that's the reason?