Issue with scrollbars in a asp:listbox

[Srilatha0406]

I have a list box with multiple values. I need a functionality to move items up/down using Ctrl+uparrow/Ctrl+downarrow. I am here by stuck with a issue when the selected item in the listbox is out of focus the scrollbars do not move correspondingly and the selected item is out of visibility.Any help is greatly appreciated.Thanks in advance. Demo