// Snow Effect Javascript
// copyright 19th November 2004, 20th July 2006 by Stephen Chapman
// permission to use this Javascript on your web page is granted
// provided that all of the code in this script (including these
// comments) is used without any alteration
// you can change the number of snow flakes if you like

var num_flakes = 40;
var snowflakes = new Array("images/snoflake.gif");

// DOM test
var aDOM = 0, ieDOM = 0, nsDOM = 0; var stdDOM = document.getElementById;
if (stdDOM) aDOM = 1; else {ieDOM = document.all; if (ieDOM) aDOM = 1; else {
var nsDOM = ((navigator.appName.indexOf('Netscape') != -1)
&& (parseInt(navigator.appVersion) ==4)); if (nsDOM) aDOM = 1;}}
function findDOM(objectId, wS) {
if (stdDOM) return wS ? document.getElementById(objectId).style:
document.getElementById(objectId);
if (ieDOM) return wS ? document.all[objectId].style: document.all[objectId];
if (nsDOM) return document.layers[objectId];
}

// window size tests
function findLivePageWidth() {return window.innerWidth != null? window.innerWidth : document.documentElement && document.documentElement.clientWidth ?       document.documentElement.clientWidth : document.body != null ? document.body.clientWidth :700;}function findLivePageHeight() {return  window.innerHeight != null? window.innerHeight : document.documentElement && document.documentElement.clientHeight ?  document.documentElement.clientHeight : document.body != null? document.body.clientHeight :500;}
function posX() {return typeof window.pageXOffset != 'undefined' ? window.pageXOffset:document.documentElement.scrollLeft? document.documentElement.scrollLeft:document.body.scrollLeft? document.body.scrollLeft:0;}
function posY() {return typeof window.pageYOffset != 'undefined' ? window.pageYOffset:document.documentElement.scrollTop? document.documentElement.scrollTop: document.body.scrollTop?document.body.scrollTop:0;}

// make it snow
var speed = 17;var movw = new Array();var movh = new Array();var move = new Array();var stepw = new Array();var steph = new Array();var posw = new Array();var posh = new Array();var dir = new Array();var winWidth;var winHeight;
function startSnow() {
	winWidth = findLivePageWidth()-75;winHeight = findLivePageHeight()-50;
	for (var i = 0; i < num_flakes; i++) {
		move[i] = 0;
		movh[i] = 12+ Math.random()*2;
		movw[i] = 11+ Math.random()*4;
		posw[i] = Math.random()*(winWidth-35)+12;
		posh[i] = Math.random()*winHeight;
		stepw[i] = 0.02 + Math.random()/10;
		steph[i] = 0.7 + Math.random();
		dir[i] = (Math.random()>0.5)?1:-1;
		document.write('<div id="snow'+ i +'" style="position: absolute; z-index: '+ i +'; visibility:hidden; "><img src="'+snowflakes[Math.floor(Math.random()*snowflakes.length)]+ '" border="0"></div>');
	}
	setTimeout("moreSnow()", speed);
}

function checkPos() {
	objstyle = findDOM('snow0',1);
	alert(objstyle.left + " / " + objstyle.top);
}

function moreSnow() {
	for (var i = 0; i < num_flakes; i++) {
		if (posh[i] > winHeight-50) {
			posw[i] = 10+ Math.random()*(winWidth-movw[i]-30);
			posh[i] = 0;
			dir[i]=(Math.random()<0.5)?1:-1;
			stepw[i] = 0.02 + Math.random()/9;
			steph[i] = 1.3 + Math.random();
		}

		dir[i] = 1;
		move[i] += stepw[i] * dir[i];

		if (Math.abs(move[i]) > 3) {
			dir[i]=-dir[i];
			// posh[i]+=Math.abs(movh[i]*move[i]);
			// posw[i]+=movw[i]*move[i];
			// move[i]=3;
		}

		objstyle = findDOM('snow'+i,1);
		objstyle.left = (posX()+posw[i] + movw[i]*move[i]/4)+'px';
		objstyle.top = (posY()+posh[i] + movh[i]*move[i]) +'px';
		// objstyle.top = (posY()+posh[i] + movh[i]*(Math.abs(Math.cos(move[i])+move[i])))+'px';
		objstyle.visibility = 'visible';

		if ((objstyle.left.replace('px', '') > findLivePageWidth()-40) || (objstyle.top.replace('px', '') > findLivePageHeight()-40)) {
			objstyle.left = 10+ Math.random()*(winWidth-movw[i]-30) + 'px';
			objstyle.top = -60 + 'px';
			posw[i] = 10+ Math.random()*(winWidth-movw[i]-30);
			posh[i] = 0;

			move[i] = 0;
		}
	}
	setTimeout("moreSnow()", speed);
}

function checkDirection() {
	alert(posX() + "+" + posw[0] + "+" + movw[0] + "*" + move[0]);
}