function rnd(){return Math.random();}
function xRnd(){return (rnd()/10);}
function yRnd(){return (2 + 2*( .5 - rnd() ));}
var letitsnow = true;
var flakes = Array("snow0.gif","snow1.gif","snow2.gif","snow3.gif");
var numflakes = 50;
var T = 50;
var dx, xPos, yPos, am, vx, vy, obj, i;
var winwidth = 640;
var winheight = 480;

function sizeIt()
{
window.winwidth = window.innerWidth?window.innerWidth:document.body.clientWidth;
window.winheight = window.innerHeight?window.innerHeight:document.body.clientHeight;
}

dx = new Array();
xPos = new Array();
yPos = new Array();
sway = new Array();
var swaymax = 10;
vx = new Array();
vy = new Array();
sizeIt();
document.write("<STYLE type=\"text/css\">\n.flk {position:absolute;top:-100;}<\/STYLE>");
for (i = 0; i < numflakes; i++)
{
        var thisflake = "" + flakes[Math.floor(rnd()*flakes.length)];
        dx[i] = 0;

        xPos[i] = rnd()*(window.winwidth-30) +10;
        yPos[i] = rnd()*window.winheight;
        sway[i] = rnd()*swaymax;
        vx[i] = xRnd();
        vy[i] = yRnd();
        document.write("<div id=\"f"+ i +"\" class=\"flk\"><img src=\"");
        document.write(thisflake + "\" 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 snowSwitch(s)
{
        if ( s == "on" )
        {
                if ( window.letitsnow != true )
                {
                        window.letitsnow = true;
                        doSnow();
                }
        } else if ( s == "off" )
        {
                window.letitsnow = false;
                hideSnow();
        }
}

function hideSnow()
{
        for (i = 0; i < numflakes; ++ i) {
                snowMove("f"+i,-100,-100);
        }
}

function doSnow() {
if (letitsnow){
        sizeIt();
        delta = (window.pageYOffset!=null)?window.pageYOffset:document.body.scrollTop;
        for (i = 0; i < numflakes; ++ i) {
                yPos[i] += vy[i];
                if (yPos[i] > window.winheight+delta-50) {
                        xPos[i] = rnd()*(window.winwidth-sway[i]-30);
                        yPos[i] = delta;
                        vx[i] = xRnd();
                        vy[i] = yRnd();
                }
                dx[i] += vx[i];
                snowMove("f"+i,xPos[i]+sway[i]*Math.cos(dx[i]),yPos[i]);
        }
        setTimeout("doSnow()", T);
}
}


window.onload=doSnow;