//nbr flocon
var no = 20;
//temps de chute
var delai = 5;
var dx = new Array(), xp = new Array(), yp = new Array();
var am = new Array(), stx = new Array(), sty = new Array();
var i;
if (document.all) {
larg_fenetre = document.body.offsetWidth;
haut_fenetre = document.body.offsetHeight;
} else {
larg_fenetre = (document.body.offsetWidth<window.innerWidth)? window.innerWidth:document.body.offsetWidth;
haut_fenetre = (document.body.offsetHeight<window.innerHeight)? window.innerHeight:document.body.offsetHeight;
}

for (i = 0; i < no; i++)
{ 
dx[i] = 0;
xp[i] = Math.random()*(larg_fenetre-80);
yp[i] = Math.random()*haut_fenetre;
am[i] = Math.random()*20;
stx[i] = 0.02 + Math.random()/10;
sty[i] = 0.7 + Math.random();

obj = document.getElementsByTagName('body')[0];
para = document.createElement("img");
var source = document.createAttribute("src");
var ident = document.createAttribute("id");
source.nodeValue = "http://creer-un-site.fr/papa-noel/snowflake.png";
ident.nodeValue = "dot" + i;
para.setAttributeNode(source);
para.setAttributeNode(ident);
obj.appendChild(para);
document.getElementById("dot" + i ).className = "flocon"
}

function neige() {
for (i = 0; i < no; i++) {
dx[i] += stx[i];
yp[i] += sty[i];
if (yp[i] > haut_fenetre-50) {
xp[i] = Math.random()*(larg_fenetre-am[i]-40);
yp[i] = 0;
}
document.getElementById("dot"+i).style.top = yp[i] + "px";
document.getElementById("dot"+i).style.left = xp[i] + am[i]*Math.sin(dx[i]) + "px";
if (!document.all) {
larg_fenetre = (document.body.offsetWidth<window.innerWidth)? window.innerWidth:document.body.offsetWidth;
haut_fenetre = (document.body.offsetHeight<window.innerHeight)? window.innerHeight:document.body.offsetHeight;
}
}
setTimeout("neige()", delai);
}

neige();