Tutorial snow effect version 2

<script type="text/javascript">

/******************************************

* Snow Effect Script- By Altan d.o.o. (http://www.altan.hr/snow/index.html)

* Visit Dynamic Drive DHTML code library (http://www.dynamicdrive.com/) for full source code

* Last updated Nov 9th, 05' by DD. This notice must stay intact for use

******************************************/

//Configure below to change URL path to the snow image

var snowsrc="URL SNOW ANDA"

// Configure below to change number of snow to render

var no = 10;

// Configure whether snow should disappear after x seconds (0=never):

var hidesnowtime = 0;

// Configure how much snow should drop down before fading ("windowheight" or "pageheight")

var snowdistance = "windowheight";

///////////Stop Config//////////////////////////////////

var ie4up = (document.all) ? 1 : 0;

var ns6up = (document.getElementById&&!document.all) ? 1 : 0;

function iecompattest(){

return (document.compatMode && document.compatMode!="BackCompat")? document.documentElement : document.body

}

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 (ns6up) {

doc_width = self.innerWidth;

doc_height = self.innerHeight;

} else if (ie4up) {

doc_width = iecompattest().clientWidth;

doc_height = iecompattest().clientHeight;

}

dx = new Array();

xp = new Array();

yp = new Array();

am = new Array();

stx = new Array();

sty = new Array();

snowsrc=(snowsrc.indexOf("dynamicdrive.com")!=-1)? "snow.gif" : snowsrc

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 (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 snowIE_NS6() { // IE and NS6 main animation function

doc_width = ns6up?window.innerWidth-10 : iecompattest().clientWidth-10;

doc_height=(window.innerHeight && snowdistance=="windowheight")? window.innerHeight : (ie4up && snowdistance=="windowheight")? iecompattest().clientHeight : (ie4up && !window.opera && snowdistance=="pageheight")? iecompattest().scrollHeight : iecompattest().offsetHeight;

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();

}

dx[i] += stx[i];

document.getElementById("dot"+i).style.top=yp[i]+"px";

document.getElementById("dot"+i).style.left=xp[i] + am[i]*Math.sin(dx[i])+"px";

}

snowtimer=setTimeout("snowIE_NS6()", 10);

}

function hidesnow(){

if (window.snowtimer) clearTimeout(snowtimer)

for (i=0; i<no; i++) document.getElementById("dot"+i).style.visibility="hidden"

}

if (ie4up||ns6up){

snowIE_NS6();

if (hidesnowtime>0)

setTimeout("hidesnow()", hidesnowtime*1000)

}

</script>