Which stylevar for the form border?

[Anyoldname]

I'm sure my forms used to have a border? Beed editing some stylevars and now its gone. Can't for the life of me guess which one it is. Its the left & right border that goes around form blocks for new threads/posts. Anyone know which stylevar I need to edit?
Or did it have a background colour that I have mistakenly changed to white?

http://img706.imageshack.us/img706/7841/vbform.png

[Anyoldname]

Anyone?

[Michael.A]

look up and download firebug for firefox..

[Anyoldname]

Thanks mad dog,

I actually have the web developers kit for firefox. It shows that the element is form .vbform block. But I can't find which stylevar referrs to this css.

EDIT: Found it! it's formrow_background :)