Simple Forum Border... Help?

[Oyobiia]

At the moment my forum look like this:

https://vborg.vbsupport.ru/external/2009/04/24.png

Is there a way to add an outside border between the forums? like this...

https://vborg.vbsupport.ru/external/2009/04/25.png

[Princeton]

add class="tborder" to <table> tag

[Oyobiia]

On which template?