does any body know why applying a theme to openbox through obconf, just changes border and menus, but not windows?

i'm using the latest arch linux

Because Openbox just displays the menus and window decorations (I assume that is what you mean with border). The content of the windows is drawn by the program (or better the respective framework) itself. So if you want to change the look of GTK programs you have to install GTK themes and configure GTK to use them. For convenience reasons I can recommend lxappearance for that, it is very lightweight and has almost no dependencies.
For QT programs you have to use QT themes, but I don't know a program to configure QT, since I really rarely use it.

You can use qtconfig that comes with QT.

oh thanks
I'm very new to openbox, lxappearance did it, i rarely use qt too, so it doesn't matter how it will look
and, can i have true transparency? openbox supports it? i guess i'll figure it out with xcompmgr