DEMÓ

KÓDJA

<SCRIPT type="text/javascript">

var snowmax=35
var snowcolor=new Array("#AAAACC","#DDDDFF","#CCCCDD","#F3F3F3","#F0FFFF")
var snowtype=new Array("Arial Black","Arial Narrow","Times","Comic Sans MS")
var snowletter="*"
var sinkspeed=0.6
var snowmaxsize=22
var snowminsize=8
var snowingzone=1

var snow=new Array()
var marginbottom
var marginright
var timer
var i_snow=0
var x_mv=new Array();
var crds=new Array();
var lftrght=new Array();
var browserinfos=navigator.userAgent
var ie5=document.all&&document.getElementById&&!browserinfos.match(/Opera/)
var ns6=document.getElementById&&!document.all
var opera=browserinfos.match(/Opera/) 
var browserok=ie5||ns6||opera

function randommaker(range) { 
 rand=Math.floor(range*Math.random())
    return rand
}

function initsnow() {
 if (ie5 || opera) {
  marginbottom = document.body.clientHeight
  marginright = document.body.clientWidth
 }
 else if (ns6) {
  marginbottom = window.innerHeight
  marginright = window.innerWidth
 }
 var snowsizerange=snowmaxsize-snowminsize
 for (i=0;i<=snowmax;i++) {
  crds[i] = 0;                     
     lftrght[i] = Math.random()*15;        
     x_mv[i] = 0.03 + Math.random()/10;
  snow[i]=document.getElementById("s"+i)
  snow[i].style.fontFamily=snowtype[randommaker(snowtype.length)]
  snow[i].size=randommaker(snowsizerange)+snowminsize
  snow[i].style.fontSize=snow[i].size
  snow[i].style.color=snowcolor[randommaker(snowcolor.length)]
  snow[i].sink=sinkspeed*snow[i].size/5
  if (snowingzone==1) {snow[i].posx=randommaker(marginright-snow[i].size)}
  if (snowingzone==2) {snow[i].posx=randommaker(marginright/2-snow[i].size)}
  if (snowingzone==3) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/4}
  if (snowingzone==4) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/2}
  snow[i].posy=randommaker(2*marginbottom-marginbottom-2*snow[i].size)
  snow[i].style.left=snow[i].posx
  snow[i].style.top=snow[i].posy
 }
 movesnow()
}

function movesnow() {
 for (i=0;i<=snowmax;i++) {
  crds[i] += x_mv[i];
  snow[i].posy+=snow[i].sink
  snow[i].style.left=snow[i].posx+lftrght[i]*Math.sin(crds[i]);
  snow[i].style.top=snow[i].posy
 
  if (snow[i].posy>=marginbottom-2*snow[i].size || parseInt(snow[i].style.left)>(marginright-3*lftrght[i])){
   if (snowingzone==1) {snow[i].posx=randommaker(marginright-snow[i].size)}
   if (snowingzone==2) {snow[i].posx=randommaker(marginright/2-snow[i].size)}
   if (snowingzone==3) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/4}
   if (snowingzone==4) {snow[i].posx=randommaker(marginright/2-snow[i].size)+marginright/2}
   snow[i].posy=0
  }
 }
 var timer=setTimeout("movesnow()",50)
}

for (i=0;i<=snowmax;i++) {
 document.write("<span id='s"+i+"' style='position:absolute;top:-"+snowmaxsize+"'>"+snowletter+"</span>")
}
if (browserok) {
 window.onload=initsnow
}
</SCRIPT>