secondly here is my code:

2. Controller tester = new Controller(true, 1);
3. 
   
4. void setup(){
5.   size(500,500);
6.   background(0);
7.   tester.addToSystem
8. }
9. 
   
10. void draw(){
11.   tester.addForces;
12.   tester.updateSystem;
13. }
14. 
    
16. public class Controller{
17.   float gravity;
18.   boolean gravityOn;
19.   
20.   
21.   Controller(boolean gravityTrue,float gravityValue){
22.     gravity = gravityValue;
23.     gravityOn = gravityTrue;
24.     vPoint tester;
25.   }
26.   
27.   void addToSystem(){
28.     tester = new vPoint(100,100);
29.   }
30.   
31.   void addForces(){
32.     if(gravityOn = true)
33.     {
34.       vPoint.y+=gravity;
35.     }
36.   }
37.   
38.   void updateSystem(){
39.   tester.update();
40.   tester.render();
41. }
42. }
45. public class vPoint{
46.    float x;
47.    float y;
48.    float oldx;
49.    float oldy;
50. 
    
51.  vPoint(float fx, float fy){ // fx is first x and ditto for y
52.   x = fx;
53.   y = fy;
54.   x = oldx = x;
55.   y = oldy = y;
56. }
57. 
    
58. 
    
59.  void update(){
60.    float tempx = x;
61.    float tempy = y;
62.    x+= x - oldx;
63.    y+= y - oldy;
64.    oldx = tempx;
65.    oldy = tempy;
66.  }
67.  
68.  void render(){
69.    stroke(255);
70.    line(x,y,oldx,oldy);
71.  }
72.  
73.  }

It is a verlet physics engine and i know the vPoint class is fine because i tested it.  I just messed up the Controller class I think can someone help me out cause this error is killing me.  I know there may be some unrelated errors in my code but i can't even check them till i fix this darn error.  BTW no arrays yet because it's faster to test on on point for now.

thanks!