Hey am new to this making my 1st skin.

I have Round Button for the Minimize, Restore down and close buttons. But theres a white background when i save it as .tga. Do i have to do something else to make it transparent? Do save it as .gif as that is transparent as well as .Png.
I use Photoshop CS2.

Also how do i change the color of the red X on the close button can i change it to a colour that matches my skin? like White cos mines has Pink white and red mixed.

Raiders