// Move the mouse across the image 
// to change its value 
 
int value = 0; 
 
void draw() { 
  fill(value); 
  rect(25, 25, 50, 50); 
} 
 
void mouseMoved() 
{ 
  value = value + 5; 
  if (value > 255) { 
    value = 0; 
  } 
}