Probleme neige java

bonjour , j ais trouver ca sur internt mais je n ais pu fair neiger que sur un petit morceau ma question est comment fair nager sur la reste de la page merci d avence

<script language=JavaScript>
/*
Snow Effect Script
Created and submitted by Altan d.o.o. (snow_AT_altan.hr, http://www.altan.hr/snow/index.html)

EDITE SUR L'EDITEUR JAVASCRIPT
http://www.editeurjavascript.com
*/

var snowsrc="file://C:/Program Files/CoffeeCup Software/Working/snow.gif"
var no = 10;
var ns4up = (document.layers) ? 1 : 0;
var ie4up = (document.all) ? 1 : 0;
var nn6up = (document.getElementById) ? 1 : 0;
var dx, xp, yp;
var am, stx, sty;
var i, doc_width = 800, doc_height = 600;

if (ns4up) {
doc_width = self.innerWidth;
doc_height = self.innerHeight;
} else if (ie4up) {
doc_width = document.body.clientWidth;
doc_height = document.body.clientHeight;
} else if (nn6up) {
doc_width = self.innerWidth;
doc_height = self.innerHeight;
}

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;
xp[i] = Math.random()*(doc_width-50);
yp[i] = Math.random()*doc_height;
am[i] = Math.random()*20;
stx[i] = 0.02 + Math.random()/10;
sty[i] = 0.7 + Math.random();
if (ns4up) {
if (i == 0) {
document.write("<layer name=dot"+ i +" left=15 top=15 visibility=show><img src='"+snowsrc+"' border=0></layer>");
} else {
document.write("<layer name=dot"+ i +" left=15 top=15 visibility=show><img src='"+snowsrc+"' border=0></layer>");
}
} else if (ie4up || nn6up) {
if (i == 0) { document.write("<div id=dot"+ i +" style=\"POSITION: absolute; Z-INDEX: "+ i +"; VISIBILITY: visible; TOP: 15px; LEFT: 15px;\"><img src='"+snowsrc+"' border=0></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() {
for (i = 0; i < no; ++ i) {
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 = 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()", 10);
}

function snowIE() {
for (i = 0; i < no; ++ i) {
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 = document.body.clientWidth;
doc_height = document.body.clientHeight;
}
dx[i] += stx[i];
document.all["dot"+i].style.pixelTop = yp[i];
document.all["dot"+i].style.pixelLeft = xp[i] + am[i]*Math.sin(dx[i]);
}
setTimeout("snowIE()", 10);
}

function snowNN6() {
for (i = 0; i < no; ++ i) {
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 = self.innerWidth;
doc_height = self.innerHeight;
}
dx[i] += stx[i];
document.getElementById("dot"+i).style.top = yp[i];
document.getElementById("dot"+i).style.left = xp[i] + am[i]*Math.sin(dx[i]);
}
setTimeout("snowNN6()", 10);
}
if (ns4up) {
snowNS();
} else if (ie4up) {
snowIE();
} else if (nn6up) {
snowNN6();
}

</SCRIPT>

</body>
</html>