/* author: Jose Pedro Pereira */
/* Creation date: 18-12-2008 */
if ((document.getElementById) &&
window.addEventListener || window.attachEvent){

(function(){

	var num = 300;	/* numero de flocos de neve */
	var timer = 30;		/* velocidade com que caiem */
	var enableinNS6 = 1;

	var y = [];
	var x = [];
	var fall = [];
	var theFlakes = [];
	var sfs = [];
	var step = [];
	var currStep = [];
	var h,w,r;
	var d = document;
	var pix = "px";
	var domWw = (typeof window.innerWidth == "number");
	var domSy = (typeof window.pageYOffset == "number");
	var idx = d.getElementsByTagName('div').length;

	if (d.documentElement.style &&
	typeof d.documentElement.style.MozOpacity == "string")
	num = 12;

	for (i = 0; i < num; i++){
		sfs[ i ] = Math.round(1 + Math.random() * 1);

		document.write('<div id="flake'+(idx+i)+'" style="position:absolute;top:0px;left:0px;width:'
		+sfs[ i ]+'px;height:'+sfs[ i ]+'px;background-color:#ffffff;font-size:'+sfs[ i ]+'px"><\/div>');

		currStep[ i ] = 0;
		fall[ i ] = (sfs[ i ] == 1)?
		Math.round(2 + Math.random() * 2): Math.round(3 + Math.random() * 2);
		step[ i ] = (sfs[ i ] == 1)?
		0.05 + Math.random() * 0.1 : 0.05 + Math.random() * 0.05 ;
	}

	if (domWw) r = window;
	else{
		if (d.documentElement &&
		typeof d.documentElement.clientWidth == "number" &&
		d.documentElement.clientWidth != 0)
		r = d.documentElement;
		else{
			if (d.body &&
			typeof d.body.clientWidth == "number")
			r = d.body;
		}
	}

	function winsize(){
		var oh,sy,ow,sx,rh,rw;
		if (domWw){
			if (d.documentElement && d.defaultView &&
			typeof d.defaultView.scrollMaxY == "number"){
				oh = d.documentElement.offsetHeight;
				sy = d.defaultView.scrollMaxY;
				ow = d.documentElement.offsetWidth;
				sx = d.defaultView.scrollMaxX;
				rh = oh-sy;
				rw = ow-sx;
			}
			else{
				rh = r.innerHeight;
				rw = r.innerWidth;
			}
			h = rh - 2;
			w = rw - 2;
		}
		else{
			h = r.clientHeight - 2;
			w = r.clientWidth - 2;
		}
	}

	function scrl(yx){
		var y,x;
		if (domSy){
			y = r.pageYOffset;
			x = r.pageXOffset;
		}
		else{
			y = r.scrollTop;
			x = r.scrollLeft;
		}
		return (yx == 0)?y:x;
	}

	function snow(){
		var dy,dx;

		for (i = 0; i < num; i++){
			dy = fall[ i ];
			dx = fall[ i ] * Math.cos(currStep[ i ]);

			y[ i ]+=dy;
			x[ i ]+=dx;

			if (x[ i ] >= w || y[ i ] >= h){
				y[ i ] = -10;
				x[ i ] = Math.round(Math.random() * w);
				fall[ i ] = (sfs[ i ] == 1)?
				Math.round(2 + Math.random() * 2): Math.round(3 + Math.random() * 2);
				step[ i ] = (sfs[ i ] == 1)?
				0.05 + Math.random() * 0.1 : 0.05 + Math.random() * 0.05 ;
			}

			theFlakes[ i ].top = y[ i ] + scrl(0) + pix;
			theFlakes[ i ].left = x[ i ] + scrl(1) + pix;

			currStep[ i ]+=step[ i ];
		}
		setTimeout(snow,timer);
	}

	function init(){
		winsize();
		for (i = 0; i < num; i++){
			theFlakes[ i ] = document.getElementById("flake"+(idx+i)).style;
			y[ i ] = Math.round(Math.random()*h);
			x[ i ] = Math.round(Math.random()*w);
		}
		snow();
	}

	if (window.addEventListener){
		window.addEventListener("resize",winsize,false);
		window.addEventListener("load",init,false);
	}
	else if (window.attachEvent){
		window.attachEvent("onresize",winsize);
		window.attachEvent("onload",init);
	}

})();
}//End.