cookie

//取得cookie
function getCookie(name) {
 var nameEQ = name + "=";
 var ca = document.cookie.split(';');//把cookie分割成组
 for(var i=0;i < ca.length;i++) {
 var c = ca[i];//取得字符串
 while (c.charAt(0)==' ') {//判断一下字符串有没有前导空格
 c = c.substring(1,c.length);//有的话，从第二位开始取
 }
 if (c.indexOf(nameEQ) == 0) {
  //如果含有我们要的name
 return unescape(c.substring(nameEQ.length,c.length)); //解码并截取我们要值
 }
 }
 return false;
}

//清除cookie
function clearCookie(name) {
 setCookie(name, "", -1);
}

//设置cookie
function setCookie(name, value, seconds, path) {
 seconds = seconds || 0; //seconds有值就直接赋值，没有为0，这个根php不一样。
 path = path || '/';
 var expires = "";
 if (seconds != 0 ) { //设置cookie生存时间
 var date = new Date();
 date.setTime(date.getTime()+(seconds*1000));
 expires = "; expires="+date.toGMTString();
 }
 document.cookie = name+"="+escape(value)+expires+"; path="+path;//转码并赋值
}