<script>//写cookies函数 作者：翟振凯
function SetCookie(name,value)//两个参数，一个是cookie的名子，一个是值
{var Days = 30; //此 cookie 将被保存 30 天var exp  = new Date();    //new Date("December 31, 9998");exp.setTime(exp.getTime() + Days*24*60*60*1000);document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
}
function getCookie(name)//取cookies函数
{var arr = document.cookie.match(new RegExp("(^| )"+name+"=([^;]*)(;|$)"));if(arr != null) return unescape(arr[2]); return null;}
function delCookie(name)//删除cookie
{var exp = new Date();exp.setTime(exp.getTime() - 1);var cval=getCookie(name);if(cval!=null) document.cookie= name + "="+cval+";expires="+exp.toGMTString();
}SetCookie ("xiaoqi", "3")
alert(getCookie('xiaoqi'));
</script>

一个非常实用的javascript读写Cookie函数一个非常实用的javascript读写Cookie函数
function  GetCookieVal(offset)
//获得Cookie解码后的值
{
var  endstr  =  documents.cookie.indexOf  (";",  offset);
if  (endstr  ==  -1)
endstr  =  documents.cookie.length;
return  unescape(documents.cookie.substring(offset,  endstr));
}
function  SetCookie(name,  value)
//设定Cookie值
{
var  expdate  =  new  Date();
var  argv  =  SetCookie.arguments;
var  argc  =  SetCookie.arguments.length;
var  expires  =  (argc  >  2)  ?  argv[2]  :  null;
var  path  =  (argc  >  3)  ?  argv[3]  :  null;
var  domain  =  (argc  >  4)  ?  argv[4]  :  null;
var  secure  =  (argc  >  5)  ?  argv[5]  :  false;
if(expires!=null)  expdate.setTime(expdate.getTime()  +  (  expires  *  1000  ));
documents.cookie  =  name  +  "="  +  escape  (value)  +((expires  ==  null)  ?  ""  :  (";  expires="+  expdate.toGMTString()))
+((path  ==  null)  ?  ""  :  (";  path="  +  path))  +((domain  ==  null)  ?  ""  :  (";  domain="  +  domain))
+((secure  ==  true)  ?  ";  secure"  :  "");
}
function  DelCookie(name)
//删除Cookie
{
var  exp  =  new  Date();
exp.setTime  (exp.getTime()  -  1);
var  cval  =  GetCookie  (name);
documents.cookie  =  name  +  "="  +  cval  +  ";  expires="+  exp.toGMTString();
}
function  GetCookie(name)
//获得Cookie的原始值
{
var  arg  =  name  +  "=";
var  alen  =  arg.length;
var  clen  =  documents.cookie.length;
var  i  =  0;
while  (i  <  clen)
{
var  j  =  i  +  alen;
if  (documents.cookie.substring(i,  j)  ==  arg)
return  GetCookieVal  (j);
i  =  documents.cookie.indexOf("  ",  i)  +  1;
if  (i  ==  0)  break;
}
return  null;
}<SCRIPT  language="javascript">
<!--
function  openpopup(){
url="popup.htm"
window.open("gonggao.htm","gonggao","width=260,height=212,left=200,top=0")
}function  get_cookie(Name)  {
var  search  =  Name  +  "="
var  returnvalue  =  "";
if  (documents.cookie.length  >  0)  {
offset  =  documents.cookie.indexOf(search)
if  (offset  !=  -1)  {
offset  +=  search.length
end  =  documents.cookie.indexOf(";",  offset);
if  (end  ==  -1)
end  =  documents.cookie.length;
returnvalue=unescape(documents.cookie.substring(offset,  end))
}
}
return  returnvalue;
}function  helpor_net(){
if  (get_cookie('popped')==''){
openpopup()
documents.cookie="popped=yes"
}
}
helpor_net()
//-->
</SCRIPT>
如果点了确定，只要不清cookie，以后访问都不会再提示，如果不点确定则每次都会提示。放在js文件里，全站包含<SCRIPT LANGUAGE="JavaScript">
<!--
var the_cookie = document.cookie;
var broken_cookie = the_cookie.split(":");
var the_visiteraccepted = unescape(broken_cookie[1]);
//
if (the_visiteraccepted=="undefined"){var tmp=confirm('中国人何时何地。');if(tmp==false){window.close();}else{var the_visiteraccepted = 1;          var the_cookie = "ILoveChina=visiteraccepted:" + escape(the_visiteraccepted);                                 document.cookie = the_cookie;}
}
//-->
</SCRIPT>