js 实现获取cookie

// js 获取cookie 值

function getCookie(c_name)
{
if(document.cookie.length>0){
   c_start=document.cookie.indexOf(c_name + "=");
   if(c_start!=-1){ 
     c_start=c_start + c_name.length+1 ;
     c_end=document.cookie.indexOf(";",c_start);
     if(c_end==-1) {
        c_end=document.cookie.length;
     }
     return unescape(document.cookie.substring(c_start,c_end));
   }
}
return "";
}

// js 设置cookie

//写cookies
function setCookie(name,value) 
{ 
 var Days = 30;
 var exp = new Date(); 
 exp.setTime(exp.getTime() + Days*24*60*60*1000);
 document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
}

// js 获取cookie

//读取cookies 
function getCookie(name) 
{ 
 var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
 
 if(arr=document.cookie.match(reg))
 
  return unescape(arr[2]); 
 else 
  return null; 
}

//删除cookies 

function delCookie(name) 
{ 
 var exp = new Date(); 
 exp.setTime(exp.getTime() - 1); 
 var cval=getCookie(name); 
 if(cval!=null) 
  document.cookie= name + "="+cval+";expires="+exp.toGMTString(); 
}

转载自： http://hi.baidu.com/phpease/item/1e2f3424e902fa3795f62bf1