how to prevent double post in vb 3.8.7

[Mubeen Ali]

hello
i am searching for a hack by which i can prevent double post.
i find some of them but they marge that posts. but i wanna a hack which stop that duplicate post stopped and a message shown that this is duplicate thread, u can post duplicate post within X time.
i tried one but by this i face database error

[ShawneyJ]

im guessing you have tried https://vborg.vbsupport.ru/showthread.php?t=203705&highlight=doublepost

but you dont like how it merges yeah?
i dont know any other mods that do what you want 100%.
hope someone else can help.