Undefined symbols for x86_64 architecture: "_ glutInit" referenced: _main in main.o / Netbeans on Mac

I start with OpenGL, and “my” first program is Sierpinski Gasket. I use Netbeans on my MacBook Pro, and I believe that I have libraries installed, but maybe they are not connected correctly.

#include <iostream>
#include <stdio.h>
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#include <GLUT/glut.h>
#include <OpenGL/glext.h>

void myinit(){
    glClearColor(1.0,1.0,1.0,1.0);
    glColor3f(1.0,0.0,0.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0.0,50.0,0.0,50.0);
    glMatrixMode(GL_MODELVIEW);
}

void display(){
    GLfloat vertices[3][2]={{0.0,0.0},{25.0,50.0},{50.0,0.0}};
    int i, j, k;
    int rand();
    GLfloat p[2]={7.5,5.0};
    glClear(GL_COLOR_BUFFER_BIT);
    glBegin(GL_POINTS);

    for(k=0; k<5000; k++){
        j=rand()*3;
        p[0]=(p[0]+vertices[j][0])/2.0;
        p[1]=(p[1]+vertices[j][1])/2.0;
        glVertex2fv(p);
    }

    glEnd();
    glFlush();
}


int main(int argc, char** argv) {
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize(500,500);
    glutInitWindowPosition(0,0);
    glutCreateWindow("Sierpinski Gasket");
    glutDisplayFunc(display);
    myinit();
    glutMainLoop();
}

Here are the compilation errors:

Undefined characters for x86_64 architecture:

"_ glutInit" referenced by:

 _main in main.o

"_ glutInitDisplayMode" referenced by:

 _main in main.o

"_ glutInitWindowSize" referenced by:

 _main in main.o

"_ glutInitWindowPosition" referenced:

 _main in main.o

"_ glutCreateWindow" referenced by:

 _main in main.o

"_ glutDisplayFunc" referenced by:

 _main in main.o

"_ glutMainLoop" referenced by:

 _main in main.o

ld: (), x86_64

collect2: ld 1

make [2]: * [dist/Debug/GNU-MacOSX/sierpinski] 1

make [1]: * [.build-conf] 2

make: * [.build-impl] 2