萤火虫儿似的鼠标特效

<script language="JavaScript">                                           
if (document.all){                                           
                                           
colours=new Array('ff0000','00ff00','3366ff','ff00ff','ffa500','ffffff','fff000')                                           
                                           
amount=colours.length;                                           
YgetDelay=0,XgetDelay=0,Ydelay=0,Xdelay=0,step=0.2,currStep=0,my=0,mx=0;                                           
document.write('<div id="ie" style="position:absolute;top:0;left:0;"><div style="position:relative">');                                           
for (i=0; i < amount; i++)                                           
document.write('<div id="iestars" style="position:absolute;top:0px;left:0px;height:50px;width:50px;font-family:Courier New;font-size:5px;color:'+colours[i]+';padding-top:20px;text-align:center">.</div>');                                           
document.write('</div></div>');                                           
ini=1;                                           
gstep=1;                                           
function iMouse(){                                           
my=event.y;mx=event.x;                                           
}                                           
document.onmousemove=iMouse                                           
function dim(){                                           
ini-=gstep;                                           
dt=setTimeout('dim()',10);                                           
if (ini < 2){                                           
clearTimeout(dt);                                           
glow();                                           
}                                           
}                                           
function glow(){                                           
ini+=gstep;                                           
gt=setTimeout('glow()',10);                                           
if (ini > 14){                                           
clearTimeout(gt);                                           
dim();                                           
}                                           
}                                           
function stars(){                                           
ie.style.top=document.body.scrollTop;                                           
for (i=0; i < amount; i++)                                           
 {                                           
 var layer=iestars[i].style;                                            
 layer.filter='glow(color='+colours[i]+', strength='+ini+')';                                           
 layer.top= Ydelay+100*Math.sin((5*Math.sin((currStep-15.99)/10))+i*70)*Math.sin((currStep)/10)*Math.cos((currStep+i*25)/10);                                            
 layer.left=Xdelay+180*Math.cos((5*Math.sin((currStep-15.99)/10))+i*70)*Math.sin((currStep)/10)*Math.cos((currStep+i*25)/10);                                           
 }                                           
currStep+=step;                                           
}                                           
function delay(){                                           
Ydelay = YgetDelay+=(my-YgetDelay)*1/20;                                           
Xdelay = XgetDelay+=(mx-XgetDelay)*1/20;                                           
stars();                                           
setTimeout('delay()',10);                                           
}                                           
delay();                                           
glow();                                           
}                                           
</script>