Hi, my name is Fernando.
I've tried to compile the following example: rectangle.c

#include <GL/glut.h>

main() {

   InitializeAWindowPlease();

   glClearColor (0.0, 0.0, 0.0, 0.0);
   glClear (GL_COLOR_BUFFER_BIT);
   glColor3f (1.0, 1.0, 1.0);
   glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
   glBegin(GL_POLYGON);
      glVertex3f (0.25, 0.25, 0.0);
      glVertex3f (0.75, 0.25, 0.0);
      glVertex3f (0.75, 0.75, 0.0);
      glVertex3f (0.25, 0.75, 0.0);
   glEnd();
   glFlush();

   UpdateTheWindowAndCheckForEvents();
}

using the following command line:

gcc -o rectangle rectangle.c

and i've obtained the followings messages:

/tmp/ccSbXgxD.o: In function `main':
rectangle.c:(.text+0x12): undefined reference to `InitializeAWindowPlease'
rectangle.c:(.text+0x3a): undefined reference to `glClearColor'
rectangle.c:(.text+0x46): undefined reference to `glClear'
rectangle.c:(.text+0x65): undefined reference to `glColor3f'
rectangle.c:(.text+0x91): undefined reference to `glOrtho'
rectangle.c:(.text+0x9d): undefined reference to `glBegin'
rectangle.c:(.text+0xbc): undefined reference to `glVertex3f'
rectangle.c:(.text+0xdb): undefined reference to `glVertex3f'
rectangle.c:(.text+0xfa): undefined reference to `glVertex3f'
rectangle.c:(.text+0x119): undefined reference to `glVertex3f'
rectangle.c:(.text+0x11e): undefined reference to `glEnd'
rectangle.c:(.text+0x123): undefined reference to `glFlush'
rectangle.c:(.text+0x128): undefined reference to `UpdateTheWindowAndCheckForEvents'
collect2: ld returned 1 exit status

I have openSuSE 10.3, and the packages of Mesa are:

Mesa-devel-7.0.1-18
MesaGLw-7.0.1-16
Mesa-7.0.1-18
Mesa-devel-static-7.0.1-18
MesaGLw-devel-7.0.1-16

Can anybody tell me what i doing wrong?

Thanks.
Fernando.-