// 获取
function getCookie(key) {
    var strcok = document.cookie , patt = new RegExp(key+'=([^;]*);?');
    return key ?( patt.test(strcok) && strcok.match(patt)[1] ) : strcok ; 
}

// 设置
function setCookie(key , value ,bay  , path ) {
   var  date = new Date();
        date.setTime(date.getTime() + (1000 * 3600 * 24 *  bay )) 
    var expires = "; expires="+date.toGMTString() + "; path=" + path ;
    document.cookie = key + '=' + value + expires ; 
}