Extensions?!?

I am learning how to use OpenGL extensions.
However, when I try to use the function glFogCoordxxx from EXT_fog_coord, Codewarrior gives me error saying that the function is undefined. I HAVE linked to the OpenGL 1.2 headers and libraries of course.

Also, I have been trying to use the secondary
color feature in 1.2 to make highlights on textures but it does absolutely nothing!

One more question, when I check for an extension and find that it isn't there, is a way I can somehow use that extension, or does it depend on my graphics card?

(By the way, I'm running a G4 Tower with MacOs 9.0.1 using a Rage 128 card and OpenGL 1.2 in C.)

Thanxxxxx!

[DJ Tricky S]

Unlike Windows or Linux, under MacOS (pre-OSX anyway) you are limited to the extensions supported by the version of OpenGL that you build & link against. You can determine whether or not you have a certain extension available to you by searching for "EXT" through your GL headers (or, as you found out, just try to use one and you find out pretty quick whether or not you have it :O)