function setup() { 

  createCanvas(600, 600);

} 

​

function draw() { 

  textSize(10);

  text("Mouse X = " +mousex,height/100,width/50);

  background(150);

  stroke(0);

  strokeWeight(7);

  x = map(mouseX,0,600,0,255);  

    line(x,0,x,600);

  stroke(255,0,0,199);

  strokeWeight(16);

  y = map(mouseY,0,600,0,440);

  line(y,0,y,600);

  stroke(0);

  strokeWeight(10);

  z= map(mouseX, 0, 600,300,600);

  line(z,0,z,600);

}