php or dhtml?

i have seen this on a few sites, and i have searched the net on how to do it, i really would like to know if there is a script or a teqnique, etc to doing this: basicly i want a coloured scroll bar, seen at evil walrus.com and isonews.com, i would like to know what is used to change it, and a website with info, also i would like to make a site with a watermarked image as the backgound, and where the main body of text is, there is a 50% transparent windo, tia

You can accomplish a lot of that through a stylesheet. I'm not sure if any of that has anything to do with php itself.

BODY{
scrollbar-3d-light-color: #FDC282;
scrollbar-arrow-color: #EAEAEA;
scrollbar-base-color: #000000;
scrollbar-dark-shadow-color: #FDC282;
scrollbar-face-color: #FD9C36;
scrollbar-highlight-color: #E8D0B5;
scrollbar-shadow-color: #FDC282;
}

This is a snippet from the stylesheet from isonews.com, it shows how you can change the style of the scroll bar.

btw, this is IE5.5+ specific. It may work with mozilla, idk. Netscape users will notice no difference. A tutorial on the subject is here :

http://wsabstract.com/howto/scrollbarcolor.shtml

It is a good one, and interactive!