修改 totalSnow 和 dropHeight来改变雪花的数量和初始显示区域的高度。肯定可以优化，但我水平太滥，而且也不太清楚到底哪个方法节约资源，要是经典论坛的小狗和LexRus来了，肯定意见一大堆，：）

</p> <style> <p>body {background:#003 url(back.png) top center no-repeat;margin:0;}</p> <p>.snowPosition {position:absolute;}</p> </style> <div id="oSnow" style="position:absolute;top:0;left:0;"></div> <p><script type="text/javascript"></p> <p>//2004-12-30 by guoshuang for snow in xi'an</p> <p>totalSnow=40; //snow numbers</p> <p>dropHeight=80;</p> <p>oMode=5;</p> <p>imgsrc="images/snowb.gif"</p> <p>var oNodes;</p> <p>function initSnow(){</p> <p>//random config the property of snow image</p> <p>document.getElementById("oSnow").innerHTML="";</p> <p> for(i=0;i<totalSnow;i++){</p> <p> snowimg=document.createElement("img");</p> <p> snowimg.src=imgsrc;</p> <p> snowimg.alt="";</p> <p> snowimg.className="snowPosition";</p> <p> snowimg.width=parseInt(Math.random()*28);</p> <p> snowimg.height=snowimg.width;</p> <p> snowimg.style.left=parseInt(Math.random()*document.body.clientWidth-28)+"px";</p> <p> snowimg.style.top=parseInt(Math.random()*dropHeight)+"px";</p> <p> document.getElementById("oSnow").appendChild(snowimg);</p> <p> }</p> <p> oNodes=document.getElementById("oSnow").childNodes;</p> <p>}</p> <p>function dropSnow(){</p> <p> if(oNodes.length==0)return;</p> <p> for(j=0;j<oNodes.length;j++){</p> <p> nowTop=oNodes[j].style.top;</p> <p> nowLeft=oNodes[j].style.left;</p> <p> nowTop=nowTop.substring(0,nowTop.length-2);</p> <p> nowLeft=nowLeft.substring(0,nowLeft.length-2);</p> <p> nowWidth=oNodes[j].clientWidth;</p> <p> oNodes[j].style.top=parseInt(nowTop)+2;</p> <p> //special show for random left right moving</p> <p> leftDistance=parseInt(Math.random()*3)</p> <p> oNodes[j].style.left=parseInt(nowLeft)-leftDistance;</p> <p> if(nowTop%oMode==0){</p> <p> if(nowWidth<1){</p> <p> //remove old node,append new one!</p> <p> document.getElementById("oSnow").removeChild(oNodes[j]);</p> <p> //new one</p> <p> snowimg=document.createElement("img");</p> <p> snowimg.src=imgsrc;</p> <p> snowimg.alt="";</p> <p> snowimg.className="snowPosition";</p> <p> snowimg.width=parseInt(Math.random()*28);</p> <p> snowimg.height=snowimg.width;</p> <p> snowimg.style.left=parseInt(Math.random()*document.body.clientWidth-28)+"px";</p> <p> snowimg.style.top=parseInt(Math.random()*dropHeight)+"px";</p> <p> document.getElementById("oSnow").appendChild(snowimg);</p> <p> }else{</p> <p> oNodes[j].style.width=nowWidth-1;</p> <p> oNodes[j].style.height=nowWidth-1;</p> <p> }</p> <p> }</p> <p> }</p> <p>}</p> <p>//init</p> <p>window.onload=function(){initSnow();setInterval(dropSnow,200)}</p> <p>window.onresize=function(){initSnow()}</p> <p></script></p> <p> [Ctrl+A 全部选择 提示：你可先修改部分代码，再按运行]

简化版，只显示，不动，拖动窗口大小，图案变化

</p> <style> <p>body {background:#003 url(back.png) top center no-repeat;margin:0;}</p> <p>.snowPosition {position:absolute;}</p> </style> <div id="oSnow" style="position:absolute;top:0;left:0;"></div> <p><script type="text/javascript"></p> <p>//2004-12-30 by guoshuang for snow in xi'an</p> <p>totalSnow=40; //snow numbers</p> <p>dropHeight=80;</p> <p>imgsrc="images/snowb.gif"</p> <p>var oNodes;</p> <p>function initSnow(){</p> <p>//random config the property of snow image</p> <p>document.getElementById("oSnow").innerHTML="";</p> <p> for(i=0;i<totalSnow;i++){</p> <p> snowimg=document.createElement("img");</p> <p> snowimg.src=imgsrc;</p> <p> snowimg.alt="";</p> <p> snowimg.className="snowPosition";</p> <p> snowimg.width=parseInt(Math.random()*28);</p> <p> snowimg.height=snowimg.width;</p> <p> snowimg.style.left=parseInt(Math.random()*document.body.clientWidth-28)+"px";</p> <p> snowimg.style.top=parseInt(Math.random()*dropHeight)+"px";</p> <p> document.getElementById("oSnow").appendChild(snowimg);</p> <p> }</p> <p> oNodes=document.getElementById("oSnow").childNodes;</p> <p>}</p> <p>//init</p> <p>window.onresize=function(){initSnow()}</p> <p></script></p> <p> [Ctrl+A 全部选择 提示：你可先修改部分代码，再按运行]