js 设置 cookie

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();

}

function getCookie(name){

    var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");

    if(arr=document.cookie.match(reg))

        return unescape(arr[2]);

    else

        return null;

}

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();

}