js操作cookie

//设置cookie
function setCookie(cname,cvalue,exdays)
{
    var d = new Date();
    d.setTime(d.getTime()+(exdays*24*60*60*1000));
    var expires = "expires="+d.toGMTString();
    document.cookie =  encodeURIComponent(cname) + "=" +  encodeURIComponent(value) + "; " + expires;
}
//获取cookie
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 "";
}

// 删除cookie
function unsetCookie(name) {
    document.cookie = name + "= ; expires=" + new Date(0);
}