Adds junk

add_junk.js

while (document.body.childNodes.length>0) {
  document.body.childNodes[0].remove();
}

var can=document.createElement("CANVAS");
can.width=1500;
can.height=1000;
can.id="t1000_500";
document.body.appendChild(can);
var ctx=can.getContext("2d");
var step=30;
var draw = function() {
  for(var x=0; x<can.width; x+=step) {
    for (var y=0;y<can.height; y+=step) {
       var rnd1=Math.floor((Math.random() * 255));
       var rnd2=Math.random();
       var clr=Math.floor(rnd1);
       var num=-1;          			
       ctx.fillStyle = "rgb("+((rnd2<num)?0:clr)+","+((rnd2<num)?200:clr)+","+((rnd2<num)?0:clr)+")";  
       ctx.fillRect(x,y,step,step);
       
    }
  }
};

var on=1;			
var to=window.setInterval(draw, 1000/20);
can.onclick = function() { 
    if (on===1) {
      clearInterval(to); 
      on=0;
    } 
    else { 
      to=window.setInterval(draw, 1000/20); 
      on=1
    }
};