Nuvole o altri oggetti che volano sul forum

http://i34.tinypic.com/23ivzbl.gif

<script language="JavaScript" type="text/javascript">
<!-- Begin
// Prelevato ed illustrato su Http://www.web-link.it
//Bubble Script by Lisa (issa@lissaexplains.com, http://lissaexplains.com)
//Based on code by Altan d.o.o. (snow@altan.hr)
//For full source code and installation instructions to this script, visit http://www.dynamicdrive.com

var no = 15; // image number or falling rate
var speed = 2; // the lower the number the faster the image moves
var snow = new Array();
snow[0] = "http://i34.tinypic.com/23ivzbl.gif"
snow[1] = "http://i34.tinypic.com/23ivzbl.gif"
snow[2] = "http://i34.tinypic.com/23ivzbl.gif"

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 = 1800;

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();
j = 0;

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\"><img src=\""+ snow[j] + "\" border=\"0\"></layer>");
               } else {
                       document.write("<layer name=\"dot"+ i +"\" left=\"15\" top=\"15\" visibility=\"show\"><img src=\""+ snow[j] + "\" 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; width:1;\"><img src=\"" + snow[j] + "\" border=\"0\"></div>");
               } else {
                       document.write("<div id=\"dot"+ i +"\" style=\"POSITION: absolute; Z-INDEX: "+ i +"VISIBILITY: visible; TOP: 15px; LEFT: 15px; width:1;\"><img src=\"" + snow[j] + "\" border=\"0\"></div>");
               }
       }
       if (j == (snow.length-1)) { j = 0; } else { j += 1; }
}

function snowNS() {  // Netscape main animation function
       for (i = 0; i < no; ++ i) {  // iterate for every dot
               yp[i] -= sty[i];                if (yp[i] < -50) {
                       xp[i] = Math.random()*(doc_width-am[i]-30);
                       yp[i] = doc_height;
                       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]+pageYOffset;
               document.layers["dot"+i].left = xp[i] +
am[i]*Math.sin(dx[i]);
       }
       setTimeout("snowNS()", speed);
}

function snowIE_NS6() {  // IE main animation function
       for (i = 0; i < no; ++ i) {  // iterate for every dot
               yp[i] -= sty[i];
               if (yp[i] < -50) {
                       xp[i] = Math.random()*(doc_width-am[i]-30);
                       yp[i] = doc_height;
                       stx[i] = 0.02 + Math.random()/10;
                       sty[i] = 0.7 + Math.random();
                       doc_width = ns6up?window.innerWidth-5:document.body.clientWidth;
                       doc_height = ns6up?window.innerHeight-5:document.body.clientHeight;
               }
               dx[i] += stx[i];
               if (ie4up){
               document.all["dot"+i].style.pixelTop = yp[i]+document.body.scrollTop;
               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]+pageYOffset;
               document.getElementById("dot"+i).style.left=xp[i] + am[i]*Math.sin(dx[i]);
               }
       }
       setTimeout("snowIE_NS6()", speed);
}

if (ns4up) {
       snowNS();
} else if (ie4up||ns6up) {
       snowIE_NS6();
}
// End -->
</script>