function update(value) {
                  position += 0.01 * sign * speed;
                  color = value;
  
                  speed = speed * ( 1  - sign * accel); 
  
                  object.translation.y = position;
                  material.diffuseColor = new SFColor(1,color,color);
  
                  if (speed < 0.1 ) sign = -1; 
                  if (position < -9) {
                           effect(value);
                           sign = 1;
                           } 
                  }