404 noise page

HTML

<canvas id="world"></canvas>
<div id="display">404</div>
<div id="title">404 Not Found...</div>

CSS

body {
  overflow:hidden;
}

canvas {
  position:absolute;
  left:0;top:0;
}
#display {
  position:absolute;
  right:5px;
  top:5px;
  color:#000;
  text-shadow:
     1px  0px #fff,
    -1px  0px #fff,
     0px  1px #fff,
     0px -1px #fff;
}

#title {
  margin:0;
  padding:0.2em;
  position:absolute;
  left:5px;
  bottom:5px;
  background:rgba(255,255,255,0.5);
  display:block;
  font-size:10px;
}

ul {
  margin:0;
  padding:0.2em;
  position:absolute;
  left:5px;
  bottom:5px;
  background:rgba(255,255,255,0.5);
}
ul > li {
  display:inline;
  font-size:12px;
}

JavaScript

// forked from mitsu322's "forked: forked from: テレビの砂嵐" http://jsdo.it/mitsu322/uy2P
// forked from mitsu322's "forked: forked from: テレビの砂嵐" http://jsdo.it/mitsu322/tQGv
// forked from gct256's "forked from: テレビの砂嵐" http://jsdo.it/gct256/FjKl
// forked from hakobera's "テレビの砂嵐" http://jsdo.it/hakobera/nZe4
var world = document.getElementById('world');
var world_cx = world.getContext('2d');
var world_w, world_h;

var display = document.getElementById('display');
var rgb = document.getElementById('rgb');
var interlace = document.getElementById('interlace');

var cv = document.createElement('canvas');
var cx = cv.getContext('2d');
var cw = cv.width = 100;
var ch = cv.height = 100;
var dt = cx.createImageData(cw, ch);
var dd = dt.data, dl = dt.width * dt.height;
var j = 0;
var status = "subindo";

function generateNoise() {
  var p = 0, i = 0;  
    if(j == 230){
        status = "descendo";
    }
    if(j==25){
        status="subindo"
    }
    if(status == "subindo"){        
    for (; i < dl; ++i) {      
    dd[p++] = c = Math.floor(Math.random() * j);
    dd[p++] = c;
    dd[p++] = c;
    dd[p++] = 255;
    }
    ++j;
    }else if(status=="descendo"){
    for (; i < dl; ++i) {      
    dd[p++] = c = Math.floor(Math.random() * j);
    dd[p++] = c;
    dd[p++] = c;
    dd[p++] = 255;
    }
    --j;    
    }
  cx.putImageData(dt, 0, 0);
}

function resize() {
  var w = window.innerWidth;
  var h = window.innerHeight;
  world_w = world.width = w >> 1;
  world_h = world.height = h >> 1;
  world.style.width = w + 'px';
  world.style.height = h + 'px'; 
}

resize();
window.addEventListener('resize', resize, false);
window.addEventListener('load', function() {
  var s = +new Date;
  generateNoise();
  world_cx.fillStyle = world_cx.createPattern(cv, 'repeat');
  world_cx.fillRect(0, 0, world_w, world_h);
  setTimeout(arguments.callee, 20);
}, false);