Thread: im newbie to opengl, help plz

I've been reading some tutorials on a tutorial website for opengl and on the first tutorial : http://fly.srk.fer.hr/~unreal/theredbook/chapter01.html

shows the user how to create a window and polygon, could some1 plz tell me how the fix this code? I get errors on "OpenAWindowPlease();" and "KeepTheWindowOnTheScreenForAWhile();"

Code:

#include <gl.h>
#include <glext.h>
#include <glu.h>

main() {

   OpenAWindowPlease();

   glClearColor(0.0, 0.0, 0.0, 0.0);
   glClear(GL_COLOR_BUFFER_BIT);
   glColor3f(1.0, 1.0, 1.0);
   glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0); 
   glBegin(GL_POLYGON);
      glVertex2f(-0.5, -0.5);
      glVertex2f(-0.5, 0.5);
      glVertex2f(0.5, 0.5);
      glVertex2f(0.5, -0.5);
   glEnd();
   glFlush();

   KeepTheWindowOnTheScreenForAWhile();
}