Cookie handling functions

function createCookie(name, value, days) {
    var expires = '',
        date = new Date();
    if (days) {
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
        expires = '; expires=' + date.toGMTString();
    }
    document.cookie = name + '=' + value + expires + '; path=/';
}
 
function readCookie(name) {
    var nameEQ = name + '=',
        allCookies = document.cookie.split(';'),
        i,
        cookie;
    for (i = 0; i < allCookies.length; i += 1) {
        cookie = allCookies[i];
        while (cookie.charAt(0) === ' ') {
            cookie = cookie.substring(1, cookie.length);
        }
        if (cookie.indexOf(nameEQ) === 0) {
            return cookie.substring(nameEQ.length, cookie.length);
        }
    }
    return null;
}
 
function eraseCookie(name) {
    createCookie(name, '', -1);
}