/**
* Sets a Cookie with the given name and value.
*
* name       Name of the cookie
* value      Value of the cookie
* [expirevalue]  Expiration date of the cookie (default: end of current session)
* [expiretype]  Legal values: "minutes", "hours", "days", "months", or "years" - indicates	
*				the units on the [expirevalue] parameter.  Default is "days".
* [path]     Path where the cookie is valid (default: path of calling document)
* [domain]   Domain where the cookie is valid
*              (default: domain of calling document)
* [secure]   Boolean value indicating if the cookie transmission requires a
*              secure transmission
*/
function setCookie(name, value, expirevalue, expiretype, path, domain, secure) {
    var expires = new Date();

    if (!isNaN(expirevalue)) {
        // Determine the expiration date on the cookie
        if (expiretype == "minutes") {
            expires.setTime(expires.getTime() + 1000 * 60 * expirevalue);
        }
        else if (expiretype == "hours") {
            expires.setTime(expires.getTime() + 1000 * 60 * 60 * expirevalue);
        }
        else if (expiretype == "days") {
            expires.setTime(expires.getTime() + 1000 * 60 * 60 * 24 * expirevalue);
        }
        else if (expiretype == "months") {
            expires.setTime(expires.getTime() + 1000 * 60 * 60 * 24 * 31 * expirevalue);
        }
        else if (expiretype == "years") {
            expires.setTime(expires.getTime() + 1000 * 60 * 60 * 24 * 365 * expirevalue);
        }
        else
            expires.setTime(expires.getTime() + 1000 * 60 * 60 * 24 * expirevalue);
    }
    document.cookie = name + "=" + escape(value) +
			"; expires=" + expires.toGMTString() +
			((path) ? "; path=" + path : "") +
			((domain) ? "; domain=" + domain : "") +
			((secure) ? "; secure" : "");
}

/**
* Gets the value of the specified cookie.
*
* name  Name of the desired cookie.
*
* Returns a string containing value of specified cookie,
*   or null if cookie does not exist.
*/
function getCookie(name) {
    var dc = document.cookie;
    var prefix = name + "=";
    var begin = dc.indexOf("; " + prefix);
    if (begin == -1) {
        begin = dc.indexOf(prefix);
        if (begin != 0) return null;
    }
    else {
        begin += 2;
    }
    var end = document.cookie.indexOf(";", begin);
    if (end == -1) {
        end = dc.length;
    }
    return unescape(dc.substring(begin + prefix.length, end));
}