<!doctype html>

<html>

<head>

<meta charset="utf-8">

<title>js煙花效果</title>

<script type="text/javascript">

document.onclick=function (ev)

{

    var oEvent=ev||event;

    var aDiv=[];

    var oDiv=null;

    var _oDiv=document.createElement('div');

    var i=0;

    var x=oEvent.clientX;

    var y=oEvent.clientY;

    _oDiv.style.position='absolute';

    _oDiv.style.background='red';

    _oDiv.style.width='3px';

    _oDiv.style.height='30px';

    _oDiv.style.left=oEvent.clientX+'px';

    _oDiv.style.top=document.documentElement.clientHeight+'px';

    document.body.appendChild(_oDiv);

    var t=setInterval(function (){

        if(_oDiv.offsetTop<=y)

        {

            clearInterval(t);

            show();

            document.body.removeChild(_oDiv);

        }

        _oDiv.style.top=_oDiv.offsetTop-30+'px';

    }, 30);

    function show()

    {

        var oDiv=null;

        for(i=0;i<100;i++)

        {

            oDiv=document.createElement('div');

            oDiv.style.width='3px';

            oDiv.style.height='3px';

            oDiv.style.background='#'+Math.ceil(Math.random()*0xEFFFFF+0x0FFFFF).toString(16);

            oDiv.style.position='absolute';

            oDiv.style.left=x+'px';

            oDiv.style.top=y+'px';

            var a=Math.random()*360;

            //oDiv.speedX=Math.random()*40-20;

            //oDiv.speedY=Math.random()*40-20;

            oDiv.speedX=Math.sin(a*180/Math.PI)*20*Math.random();

            oDiv.speedY=Math.cos(a*180/Math.PI)*20*Math.random();

            document.body.appendChild(oDiv);

            aDiv.push(oDiv);

        }

    }

    setInterval(doMove, 30);

    function doMove()

    {

        for(i=0;i<aDiv.length;i++)

        {

            aDiv[i].style.left=aDiv[i].offsetLeft+aDiv[i].speedX+'px';

            aDiv[i].style.top=aDiv[i].offsetTop+aDiv[i].speedY+'px';

            aDiv[i].speedY+=1;

            if(aDiv[i].offsetLeft<0 || aDiv[i].offsetLeft>document.documentElement.clientWidth || aDiv[i].offsetTop<0 || aDiv[i].offsetTop>document.documentElement.clientHeight)

            {

                document.body.removeChild(aDiv[i]);

                aDiv.splice(i, 1);

            }

        }

    }

};

</script>

</head>

<body style="overflow:hidden; background:black;">

</body>

</html>