var no = 20; // snow number 
var speed = 1; // smaller number moves the snow faster 
var snowflake = "http://w1.loxa.com.tw/km1234/fly.gif"; 

var ns4up = (document.layers) ? 1 : 0; // browser sniffer 
var ie4up = (document.all) ? 1 : 0; 
var dx, xp, yp; // coordinate and position variables 
var am, stx, sty; // amplitude and step variables 
var i, doc_width = 1024, doc_height = 764; 
if (ns4up) { 
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\" "); 
document.write("top=\"15\" visibility=\"show\"><img src=\""); 
document.write(snowflake + "\" border=\"0\"></layer>"); 
} else { 
document.write("<layer name=\"dot"+ i +"\" left=\"15\" "); 
document.write("top=\"15\" visibility=\"show\"><img src=\""); 
document.write(snowflake + "\" border=\"0\"></layer>"); 
} 
} else if (ie4up) { 
if (i == 0) { 
document.write("<div id=\"dot"+ i +"\" style=\"POSITION: "); 
document.write("absolute; Z-INDEX: "+ i +"; VISIBILITY: "); 
document.write("visible; TOP: 15px; LEFT: 15px;\"><img src=\""); 
document.write(snowflake + "\" border=\"0\"></div>"); 
} else { 
document.write("<div id=\"dot"+ i +"\" style=\"POSITION: "); 
document.write("absolute; Z-INDEX: "+ i +"; VISIBILITY: "); 
document.write("visible; TOP: 15px; LEFT: 15px;\"><img src=\""); 
document.write(snowflake + "\" 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] = 0.7 + 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()", speed); 
} 
function snowIE() { // IE 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 = 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()", speed); 
} 
if (ns4up) { 
snowNS(); 
} else if (ie4up) { 
snowIE(); 
}