雪花的代码

Image0 = new Image();
Image0.src = "http://photos.album.juexiang.com/54/2d/81/bec92ef/tn_1148538971313.jpg";
Amount = 12;
Ymouse = -50;
Xmouse = -50;
Ypos = new Array();
Xpos = new Array();
Speed = new Array();
rate = new Array();
grow = new Array();
Step = new Array();
Cstep = new Array();
nsSize = new Array();
ns = (document.layers)?1:0;
(document.layers)?window.captureEvents(Event.MOUSEMOVE):0;
function Mouse(evnt) {
Ymouse=(document.layers)?evnt.pageY-20:event.y-20;
Xmouse=(document.layers)?evnt.pageX:event.x;
}
(document.layers)?window.onMouseMove=Mouse:document.onmousemove=Mouse;
for (i = 0; i < Amount; i++) {
Ypos[i] = Ymouse;
Xpos[i] = Xmouse;
Speed[i] = Math.random()*4+1;
Cstep[i] = 0;
Step[i] = Math.random()*0.1+0.05;
grow[i] = 8;
nsSize[i] = Math.random()*15+5;
rate[i] = Math.random()*0.5+0.1;
}
if (ns) {
for (i = 0; i < Amount; i++) {
document.write("");
   }
}
else {
document.write('');
for (i = 0; i < Amount; i++) {
document.write('');
}
document.write('');
}
function MouseBubbles() {
var hscrll = (document.layers)?window.pageYOffset:document.body.scrollTop;
var wscrll = (document.layers)?window.pageXOffset:document.body.scrollLeft;
for (i = 0; i < Amount; i++){
sy = Speed[i] * Math.sin(270 * Math.PI / 180);
sx = Speed[i] * Math.cos(Cstep[i] * 4);
Ypos[i] += sy;
Xpos[i] += sx;
if (Ypos[i] < -40) {
Ypos[i] = Ymouse;
Xpos[i] = Xmouse;
Speed[i] = Math.random() * 6 + 4;
grow[i] = 8;
nsSize[i] = Math.random() * 15 + 5;
}
if (ns) {
document.layers['sn'+i].left = Xpos[i] + wscrll;
document.layers['sn'+i].top = Ypos[i] + hscrll;
}
else {
si[i].style.pixelLeft = Xpos[i] + wscrll;
si[i].style.pixelTop = Ypos[i] + hscrll;
si[i].style.width = grow[i];
si[i].style.height = grow[i];
}
grow[i] += rate[i];
Cstep[i] += Step[i];
if (grow[i] > 24) grow[i] = 25;
}
setTimeout('MouseBubbles()', 10);
}
MouseBubbles();