text: def setup():
      size(500, 500)
      smooth()
      background(0)
      strokeWeight(1)
      
  i=0
  k=1
  flug=1
  
  def upDate():
      global i, k, flug
      i=i+k
      if(i==255):
          k=-1
      if(i==0):
          k=1
          
  def draw():
      global i, k, flug
      stroke(i, 20)
      myRandom1 = random(-20, 20)
      myRandom2= random(-20, 20)
          
      myY1=mouseY-myRandom1
      myY2=mouseY+myRandom2
      line(0, myY1, 500, myY2)
      upDate()
  