Javascript实现鼠标点击冒泡特效

Onload= function() {
 var click_cnt = 0;
 var $html = document.getElementsByTagName("html")[0];
 var $body = document.getElementsByTagName("body")[0];
 $html.Onclick= function(e) {
 var $elem = document.createElement("b");
 $elem.style.color = "#E94F06";
 $elem.style.zIndex = 9999;
 $elem.style.position = "absolute";
 $elem.style.select = "none";
 var x = e.pageX;
 var y = e.pageY;
 $elem.style.left = (x - 10) + "px";
 $elem.style.top = (y - 20) + "px";
 clearInterval(anim);
 switch (++click_cnt) {
  case 10:
  $elem.innerText = "OωO";
  break;
  case 20:
  $elem.innerText = "(&＃3665;&＃8226;&＃769; &＃8704; &＃8226;&＃768;&＃3665;)";
  break;
  case 30:
  $elem.innerText = "(&＃3665;&＃8226;&＃769; &＃8323; &＃8226;&＃768;&＃3665;)";
  break;
  case 40:
  $elem.innerText = "(&＃3665;&＃8226;&＃768;_&＃8226;&＃769;&＃3665;)";
  break;
  case 50:
  $elem.innerText = "（￣へ￣）";
  break;
  case 60:
  $elem.innerText = "(╯°口°)╯(┴—┴";
  break;
  case 70:
  $elem.innerText = "&＃2798;( &＃7506;&＃780;皿&＃7506;&＃780; )&＃4304;";
  break;
  case 80:
  $elem.innerText = "╮(&＃65377;>口<&＃65377;)╭";
  break;
  case 90:
  $elem.innerText = "( &＃3591; &＃7506;&＃780;皿&＃7506;&＃780;)&＃3591;&＃8316;³&＃8332;&＃8323;";
  break;
  case 100:
  case 101:
  case 102:
  case 103:
  case 104:
  case 105:
  $elem.innerText = "(&＃42022;°&＃7620;д°&＃7621;)";
  break;
  default:
  $elem.innerText = "&＃10084;";
  break;
 }
 $elem.style.fOntSize= Math.random() * 10 + 8 + "px";
 var increase = 0;
 var anim;
 setTimeout(function() {
  anim = setInterval(function() {
  if (++increase == 150) {
   clearInterval(anim);
   $body.removeChild($elem);
  }
  $elem.style.top = y - 20 - increase + "px";
  $elem.style.opacity = (150 - increase) / 120;
  }, 8);
 }, 70);
 $body.appendChild($elem);
 };
};