can anybody help me figure out how to get the tips of the tree branches to follow the mouse in this script? i have tried to use an example and create a 'void mousefollow' however nothing happens!

Tree branches;

void setup() {
 size(500,500);
 smooth();  
 branches = new Tree (6,5);
}
void draw() {
 background(192);
 stroke(255);
 branches.draw();
}
class Tree
{
 float m = 100;
 float n = 100;
 float x2= width/2;
 float y2= height/2;

 float dx;
 float dy;

 int frame=0;  
 float theta;
 float branch;
 float branchlength;
 float a;
 float y;

 Tree (float x, float s)
 {
   a = x; // this controls the angle of the branches
   theta = radians(a);
   branchlength = (height/s);  
   branch=y;
 }
 void draw () {
   translate(x2,y2);
   // Start the recursive branching!
   branch(branchlength);
   mousefollow(x2,y2); //think this is wrong???
 }
 void branch (float y){
   // Each branch will be 0.7 the size of the previous one
   y=y*0.7;
   if (y > 10) {
     pushMatrix();    
     rotate(a);  
     line(0,0,0,-y);  
     translate(0,-y);
     branch(y);
     popMatrix();  
     //  branch off to left
     pushMatrix();
     rotate(-a+0.6);
     line(0,0,0,-y+2);
     translate(0,-y+2);
     branch(y+0.4);
     popMatrix();
   }
 }
 //this is taken from the reach1 example.
 void mousefollow(float m,float n){
   float dx = mouseX - m; //position of mousex
   float dy = mouseY - n; //position of mousey
   float angle1 = atan2(dy, dx);  //angle of the branches
   float tx = mouseX - cos(angle1) * branchlength;  
float ty = mouseY - sin(angle1) * branchlength;

   dx = tx - x2;
   dy = ty - y2;

   float angle2 = atan2(dy, dx);  
   m = x2 + cos(angle2) * branchlength;
   n = y2 + sin(angle2) * branchlength;
 }
}