var no = 35; // number of snowflakes
var speed = 10; // the smaler, the faster move snowflakes
var snowflake = "http://www.tanzen-in-kiel.de/cms_2_7/media/image/snow.gif"; // picture source
var ns4b = (document.layers) ? 1 : 0; // Netscape4.x
var b4up = (document.all) ? 1 : 0; // MSIE4, Opera5, Netccape5
var dx, xp, yp; // coordinate and position variables
var am, stx, sty; // amplitude and step variables
var snowobj;
var i, doc_width = 800, doc_height = 600; // 800x600 screen-default

if (ns4b) {
doc_width = self.innerWidth;
doc_height = self.innerHeight;
} else if (b4up) {
doc_width = document.body.clientWidth;
doc_height = document.body.clientHeight;
} else {
doc_width = window.innerWidth;
doc_height = window.innerHeight;
b4up = 1;
}// if

dx = new Array();
xp = new Array();
yp = new Array();
am = new Array();
stx = new Array();
sty = new Array();
snowobj = new Array();

for (i=0; i<no; ++i) { // iterate for every snowflake
dx[i] = 0; // set coordinate variables
xp[i] = Math.random()*(doc_width-50); // set position variables
yp[i] = Math.random()*doc_height;
am[i] = Math.random()*20; // set amplitude variables
stx[i] = 0.02 + Math.random()/10; // set step variables
sty[i] = 0.7 + Math.random(); // set step variables
if (ns4b) { // set layers
document.write("<LAYER NAME=\"flake"+ i +"\" LEFT=\"15\" TOP=\"15\" VISIBILITY=\"show\"><IMG SRC=\""+ snowflake +"\" BORDER=0></LAYER>");
} else if (b4up) {
document.write("<DIV ID=\"flake"+ i +"\" STYLE=\"position:absolute; z-index:"+ i +"; visibility:visible; top:15px; left:15px;\"><IMG SRC=\""+ snowflake +"\" BORDER=0></DIV>");
snowobj[i] = eval (document.getElementById("flake"+i).style);
}//if
}//for

function snowNS() { // Netscape4 main animation function
for (i=0; i<no; ++i) { // iterate for every snowflake
yp[i] += sty[i];
if (yp[i] > doc_height-50) {
xp[i] = Math.random()*(doc_width-am[i]-30);
yp[i] = 0;
stx[i] = 0.02 + Math.random()/10;
sty[i] = 0.7 + Math.random();
}//if
dx[i] += stx[i];
document.layers["flake"+i].top = yp[i];
document.layers["flake"+i].left = xp[i] + am[i]*Math.sin(dx[i]);
}//for
setTimeout("snowNS()", speed);
}//snowNS

function snowDocument() { // MSIE4, Opera5, Netscape5 main animation function
for (i=0; i<no; ++i) { // iterate for every flake
yp[i] += sty[i];
if (yp[i] > doc_height-50) {
xp[i] = Math.random()*(doc_width-am[i]-30);
yp[i] = 0;
stx[i] = 0.02 + Math.random()/10;
sty[i] = 0.7 + Math.random();
}//if
dx[i] += stx[i];
snowobj[i].top = yp[i];
snowobj[i].left = xp[i] + am[i]*Math.sin(dx[i]);
}//for
setTimeout("snowDocument()", speed);
}//snowDocument

if (ns4b) { // Netscape4
snowNS();
} else if (b4up) { // MSIE4, Opera5, Netscape5
snowDocument();
}//if