js cookie缓存处理

function setCookie(cnameList,cvalueList,exdays){
    var d = new Date();
    d.setTime(d.getTime()+(exdays*24*60*60*1000));
    var expires = "expires="+d.toGMTString();
    var tem = '';
    for(var i=0;i<cnameList.length;i++){
        tem += cnameList[i] + "=" +cvalueList[i] + "; "
    }
    //注意下面写cookie ，cookie原值会被覆盖
    document.cookie = tem + expires;  
}
function getCookie(cname){
    var name = cname + "=";
    var ca = document.cookie.split(';');
    for(var i=0; i<ca.length; i++) {
        var c = ca[i].trim();
        if (c.indexOf(name)==0){
            return c.substring(name.length,c.length);
        }
    }
    return "";
}