thank you chaosben
i meant the result is not the same as with the TListView .
the code does a TListView auto-scroll from a Second Form where i have 2 buttons ( UP_Scroll and DOWN_Scroll ) of course via the Msg .
the code works good with the TListView and i can see the UP_scroll and DOWN_scroll with IT . but with TVirtualStringTree
if you want i can attache a little sample of IT ?