// Click on the window to give it focus 
// and press the 'B' key 
 
void draw() { 
  if(keyPressed) { 
    if (key == 'b' || key == 'B') { 
      fill(0); 
    } 
  } else { 
    fill(255); 
  } 
  rect(25, 25, 50, 50); 
}