var snowflake = "snow_flake.gif";
var no = 16; 
var speed = 16; 
var dx, xp, yp; 
var am, stx, sty; 
var obj, i, doc_width = 800, doc_height = 600;

function winSize() {
doc_width = window.innerWidth?window.innerWidth:document.body.clientWidth;
doc_height = window.innerHeight?window.innerHeight:document.body.clientHeight;
}

dx = new Array();
xp = new Array();
yp = new Array();
am = new Array();
stx = new Array();
sty = new Array();
winSize();
document.write("<STYLE type=\"text/css\">.flake {position:absolute;top:-200;}</STYLE>");
for (i = 0; i < no; i++) { 
dx[i] = 0; 
xp[i] = Math.random()*(doc_width-30) +10; 
yp[i] = Math.random()*doc_height;
am[i] = Math.random()*20; 
stx[i] = 0.02 + Math.random()/10; 
sty[i] = 0.7 + Math.random(); 
document.write("<div id=\"dot"+ i +"\" class=\"flake\"><img src=\"");
document.write(snowflake + "\" border=\"0\"></div>");
}

function snowMove(id,left,top) {
obj = document.getElementById?document.getElementById(id).style:
document.all?document.all[id].style:
document.layers?document.layers[id]:null;
if (obj) {
obj.left=left;
obj.top=top;
}
}

function snow() {
winSize();
doc_scroll = (window.pageYOffset!=null)?window.pageYOffset:document.body.scrollTop;
for (i = 0; i < no; ++ i) { 
yp[i] += sty[i];
if (yp[i] > doc_height+doc_scroll-50) {
xp[i] = Math.random()*(doc_width-am[i]-30);
yp[i] = doc_scroll;
stx[i] = 0.02 + Math.random()/10;
sty[i] = 0.7 + Math.random();
}
dx[i] += stx[i];
snowMove("dot"+i,xp[i]+am[i]*Math.sin(dx[i]),yp[i]);
}
setTimeout("snow()", speed);
}