Projection Matrix

Hi Im basically building a 3d engine (very simple one) using software rendering (no opengl or directx) for learning purposes. The 3d engine has one simple rendering method thats suppose to render a point from world space to the 2d space (monitor) i believe i got the rendering working properly, but it has no perspective i believe i need a perspective matrix can you pros help me build one

  public static Pixel2D render(Camera c, Pixel3D p) {
    //matrix transformations (with euler style rotation)
    //fm = pm * cm * wm * point
    double fm[][];
    double om[][] = createMatrix(4, 1);
    double cm[][];
    double ctm[][] = createIdentityMatrix(4); //camera translation
    double crxm[][] = createIdentityMatrix(4); //camera x-axis rotation
    double crym[][] = createIdentityMatrix(4); //camera y-axis rotation
    double crzm[][] = createIdentityMatrix(4); //camera z-axis rotation
    double pm[][] = createIdentityMatrix(4); //perspective matrix

    double rx = Math.toRadians(c.getRoll());
    double ry = Math.toRadians(c.getPitch());
    double rz = Math.toRadians(c.getYaw());

    //camera matrix
    //translation
    ctm[0][3] = c.getX();
    ctm[1][3] = c.getY();
    ctm[2][3] = c.getZ();

    //roll
    crxm[1][1] = Math.cos(rx);
    crxm[1][2] = Math.sin(rx);
    crxm[2][1] = -Math.sin(rx);
    crxm[2][2] = Math.cos(rx);

    //pitch
    crym[0][0] = Math.cos(ry);
    crym[0][2] = -Math.sin(ry);
    crym[2][0] = Math.sin(ry);
    crym[2][2] = Math.cos(ry);

    //yaw
    crzm[0][0] = Math.cos(rz);
    crzm[0][1] = Math.sin(rz);
    crzm[1][0] = -Math.sin(rz);
    crzm[1][1] = Math.cos(rz);

    cm = multiplyMatrix(crxm, crym);
    cm = multiplyMatrix(cm, crzm);
    cm = multiplyMatrix(cm, ctm);

    //projection matrix
    pm[3][2] = 1;
    pm[3][3] = 0;

    //object matrix (point)
    om[0][0] = p.getX();
    om[1][0] = p.getY();
    om[2][0] = p.getZ();
    om[3][0] = 1;

    //we have no world matrix

    //fm = multiplyMatrix(pm, cm);
    //fm = multiplyMatrix(cm, om);

    fm = multiplyMatrix(cm, om);

    return new Pixel2D( (int) fm[0][0], (int) fm[1][0], p.getColour());
  }

for complete source code so far: 3D Engine Applet Source Code