// Original:  Altan (snow@altan.hr)

var no = 10; // snow number
var speed = 60; // smaller number moves the snow faster
var snowflake = "http://www.modding-faq.de/Forum/Themes/classic/images/snow.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 = 400;

if (ns4up||ns6up) {
	doc_width = self.innerWidth;
//	doc_height = self.innerHeight/2;
} else if (ie4up) {
	doc_width = document.body.clientWidth;
//	doc_height = document.body.clientHeight/2;
}

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||ns6up) {
		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();
		}
		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();
   		}
   		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] + 'px';
   			document.getElementById("dot"+i).style.left=(xp[i]+am[i]*Math.sin(dx[i])) + 'px';
   		}
   	}
	setTimeout("snowIE()", speed);
}

if (ns4up) {
	snowNS();
} else if (ie4up||ns6up) {
	snowIE();
}