He probado mi intro guardandolo en un blog de notas en formato html y funciona bien, a falta de algun detalle que me falta de poner. Pero ahora no se subirlo a PWG, o donde subirlo o si necesito cambiar algo. el codigo es
<html>
<BODY>
<body bgcolor="yellow">
<br>
<center>
<a href="http://www.clubatletismosinver.es.tl">
<img src="https://dl.dropbox.com/u/40123605/123.jpg"<SINVER></a>
</center>
<script language="JavaScript1.2">
/******************************************
* Snow Effect Script- By Altan d.o.o. (snow@altan.hr,
http://www.altan.hr/snow/index.html)
* Visit Dynamic Drive (http://www.dynamicdrive.com/) for full source code
* Modified Dec 31st, 02' by DD. This notice must stay intact for use
******************************************/
//Configure below to change URL path to the snow image
var snowsrc="https://dl.dropbox.com/u/109162390/victor.gif"
// Configure below to change number of snow to render
var no = 6;
var ns4up = (document.layers) ? 1 : 0; // browser sniffer
var ie4up = (document.all) ? 1 : 0;
var ns6up = (document.getElementById&&!document.all) ? 1 : 0;
var dx, xp, yp; // coordinate and position variables
var am, stx, sty; // amplitude and step variables
var i, doc_width = 800, doc_height = 600;
if (ns4up||ns6up) {
doc_width = self.innerWidth;
doc_height = self.innerHeight;
} else if (ie4up) {
doc_width = document.body.clientWidth;
doc_height = document.body.clientHeight;
}
dx = new Array();
xp = new Array();
yp = new Array();
am = new Array();
stx = new Array();
sty = new Array();
for (i = 0; i < no; ++ i) {
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 (ns4up) { // set layers
if (i == 0) {
document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><a href=\"http://dynamicdrive.com/\"><img src='"+snowsrc+"' border=\"0\"><\/a><\/layer>");
} else {
document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><img src='"+snowsrc+"' border=\"0\"><\/layer>");
}
} else if (ie4up||ns6up) {
if (i == 0) {
document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><a href=\"http://dynamicdrive.com\"><img src='"+snowsrc+"' border=\"0\"><\/a><\/div>");
} else {
document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><img src='"+snowsrc+"' border=\"0\"><\/div>");
}
}
}
function snowNS() { // Netscape main animation function
for (i = 0; i < no; ++ i) { // iterate for every dot
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] = 0.15 + Math.random();
doc_width = self.innerWidth;
doc_height = self.innerHeight;
}
dx[i] += stx[i];
document.layers["dot"+i].top = yp[i];
document.layers["dot"+i].left = xp[i] + am[i]*Math.sin(dx[i]);
}
setTimeout("snowNS()", 20);
}
function snowIE_NS6() { // IE and NS6 main animation function
for (i = 0; i < no; ++ i) { // iterate for every dot
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();
doc_width = ns6up?window.innerWidth : document.body.clientWidth;
doc_height = ns6up?window.innerHeight : document.body.clientHeight;
}
dx[i] += stx[i];
if (ie4up){
document.all["dot"+i].style.pixelTop = yp[i];
document.all["dot"+i].style.pixelLeft = xp[i] + am[i]*Math.sin(dx[i]);
}
else if (ns6up){
document.getElementById("dot"+i).style.top=yp[i];
document.getElementById("dot"+i).style.left=xp[i] + am[i]*Math.sin(dx[i]);
}
}
setTimeout("snowIE_NS6()", 20);
}
if (ns4up) {
snowNS();
} else if (ie4up||ns6up) {
snowIE_NS6();
}
</script>
</html>
controlar extra 
