OpenGL functions are undefined in VS2012 express - c++

Question

I'm attempting to use some OpenGL functions in Visual Studio 2012 express, my code looks like this:
#include <Windows.h>
#include <iostream>
#include <gl/GL.h>
#include <fstream>
void saveScreen()
{
//code to define some variables, nWidth, nHeight and Buffer.
glreadbuffer ( GL_BACK ); //which buffer we are reading from.
glreadpixels ( 0, 0, nWidth, nHeight, GL_RGB, GL_UNSIGNED_BYTE, (GLvoid *Buffer);
//do something with buffer data
return;
}
According to internet research, my code is correct, apart from glreadpixels apparently expects more expressions and )'s, but i think i can work that out myself.
When i try to compile and run i get errors saying both glreadbuffer and glreadpixels are undefined. I cant find anything that tells me what to do apart from #including windows.h and gl/gl.h and OpenGL should work.
Thanks in advance for any help :)
Edit:
Thanks for replying, I added these lines to the Additional dependancys of the linker:
opengl32.lib
glu32.lib
and properly capitalised the function calls
That seems to have solved the problem.

Answer 1

The functions glreadbuffer() and glreadpixels do not exist in OpenGL. The API uses CamelCase function name style, so these function names are spelled glReadBuffer() and glReadPixels().

Answer 2

This is how you correctly link in visual studio 12:
The first thing you create is a folder somewhere called "dev" (or really any name). In that folder you extract "freeglut"(only if you want a windowing toolkit) and "glew" (the openGL extension wrangler, this loads the gl functions).
After that you open a new project in VS12 and rightclick on the project->properties
Under VC++ properties click on "Include directories" and add the path to your dev/glew/include folder and your dev/freeglut/include. Make sure your path is 100% correct!
Then click on "Library directories" and add these 2 paths: dev/glew/lib and dev/freeglut/lib.
Then go to C/C++ and click on additional include directories and add these 2 paths:dev/glew/include and dev/freeglut/include.
Then go to linker and add the lib folders in "additional library directories" this is a tricky one because you need to link to the correct version: \dev\glew\lib\Release\Win32
Then try your code again, if that doesn't work, try source code from the internet.
Also if you copied the folders without changing there name you should include "GL/glew.h"
These steps are required for each project that uses openGL.