动态CSS站点教程：多个页面样式提供浏览者选择

在cnbruce''s blog上看到这个即时换STYLE的代码,觉得不错就COPY过来备用.
在见的例子就是:一个站点上有多个页面样式提供浏览者选择.同时,在选择了某样式后,再次打开该页面时,将仍然保持该样式.自然会想到了Cookie技术。

程序代码
<HTML>
<HEAD>
<link ID="skin" rel="stylesheet" type="text/css">
<TITLE>换肤技术</TITLE>
<SCRIPT LANGUAGE=javascript>
<!--
function SetCookie(name,value){
var argv=SetCookie.arguments;
var argc=SetCookie.arguments.length;
var expires=(2<argc)?argv[2]:null;
var path=(3<argc)?argv[3]:null;
var domain=(4<argc)?argv[4]:null;
var secure=(5<argc)?argv[5]:false;
document.cookie=name+"="+escape(value)+((expires==null)?"":("; expires="+expires.toGMTString()))+((path==null)?"":("; path="+path))+((domain==null)?"":("; domain="+domain))+((secure==true)?"; secure":"");
}

function GetCookie(Name) {
var search = Name + "=";
var returnvalue = "";
if (document.cookie.length > 0) {
offset = document.cookie.indexOf(search);
if (offset != -1) {
offset += search.length;
end = document.cookie.indexOf(";", offset);
if (end == -1)
end = document.cookie.length;
returnvalue=unescape(document.cookie.substring(offset,end));
}
}
return returnvalue;
}

var thisskin;
thisskin=GetCookie("nowskin");
if(thisskin!="")
skin.href=thisskin;
else
skin.href="css.css";

function changecss(url){
if(url!=""){
skin.href=url;
var expdate=new Date();
expdate.setTime(expdate.getTime()+(24*60*60*1000*30));
//expdate=null;
//以下设置COOKIES时间为1年,自己随便设置该时间..
SetCookie("nowskin",url,expdate,"/",null,false);
}
}
//-->
</SCRIPT>
</HEAD>
<BODY>

<P>请选择下面的下拉菜单测试换肤效果</P>

<a href=# onclick="changecss(''css.css'')">css.css</a>
<a href=# onclick="changecss(''css1.css'')">css1.css</a>
<a href=# onclick="changecss(''css2.css'')">css2.css</a>
<a href=# onclick="changecss(''css3.css'')">css3.css</a>
<br>

<select onchange="changecss(this.value)">
<option>选择样式单文件</option>
<script language="javascript">
var csss=new Array();
csss[0]="css.css";
csss[1]="css1.css";
csss[2]="css2.css";
csss[3]="css3.css";
var i;
for(i=0;i<4;i++)
if(thisskin==csss[i])
document.write("<option value=\""+csss[i]+"\" selected>"+csss[i]+"样式单文件</option>");
else
document.write("<option value=\""+csss[i]+"\">"+csss[i]+"样式单文件</option>");
</script>
</select>
</BODY>
</HTML>