Refresh listbox in realtime

How can I add or exclude an item from a listbox or combobox (installopitons) without restarting the program?
(Refresh in real time means, for eg., when you mark a checkbox and disable or enable other HWND.) 🙄

You need to use the LB_ADDSTRING (ListBox) or CB_ADDSTRING (ComboBox) with SendMessage. There are also DELETESTRING messages.

-Stu