// read cookie
function readCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for (var i = 0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0) == ' ') c = c.substring(1, c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
    }
    return null;
}
//read parameter in href
function readParameter(name, href) {
    var nameEQ = name + "=";
    if (href.indexOf("?") != -1) {
        href = href.substring(href.indexOf("?") + 1);
        var parts = href.split("&");
        for (var i = 0; i < parts.length; i++) {
            if (parts[i].indexOf(nameEQ) == 0) {
                return parts[i].split("=")[1];
            }
        }
    }
    return null;
}