How to Change the Appearance of Number Slider?

[FAU78]

The code of number slider is here:
[url]http://luabin.foszor.com/code/addons/derma/lua/vgui/DNumSlider.lua[/url]

I want to change the properties of it, such as change skin pictures, or make the slider vertical. And I want to know that:

Which directory this file needs to be put, so that when I use vgui.Create("DNumSlider"), the properties that I changed will appear? Now I put them into / addons / derma / lua / vgui /, but it doesn't work?

By the way, is there any tutorial that tell people where to store those files? Now I only know the function of lua\autorun\client....

Thanks!

[FAU78]

Thanks. Read them several times...

But still can not find how to make new elements...

[FAU78]

Er... Thanks...