Paul Stephens' JavaScript cookie handling functions

JavaScript cookie handling functions - 'Classic' Edition.

These functions are designed to make it easy to store and retrieve a single JavaScript variable or value as a cookie. They use an old-style function-call interface, rather than the object-oriented structure of the newer function set (TIP - use the object versions if you want multi-field cookies and easy multi-cookie handling).

Instant Example:

var Uname = "Jane"
setCookie("UserName", Uname, 365, "/") // Write 'UserName=Jane' cookie to disk
Uname = getCookie("UserName") // Read value of "UserName" cookie into variable
deleteCookie("UserName") // Delete cookie from disk

Adding the functions to your web pages.
There are two ways to build these functions into your web pages:

Copy the source code from further down this page, then paste it into a <script></script> block in the <head> section of your page. You'll need to paste the code into every page in which you want to handle cookies. Important note for FrontPage users: don't paste the source straight from the clipboard into FrontPage's HTML view - it'll come out as formatted HTML. Instead, paste the source into Windows Notepad first, then copy from Notepad into FrontPage.
Copy the source code from further down this page, paste it into a text editor (such as Windows Notepad), then save it as a file called 'pcpckclassic.js'. Note - don't add any <script></script> tags to the source!

Now you can link the source file to your pages, by adding these tags to their <head> sections:

<script language="javascript" src="pcpckclassic.js">
</script>

Note that you must include the </script> tag. This method only works with version 3.0 and later of Navigator and IE.

Function specifications.

setCookie(Name, Value, Lifespan, Path) Creates a new cookie, or updates an existing one
Parameter	Data Type	Meaning
Name	String	Cookie name
Value	String or number	Cookie value
Lifespan (Optional)	Number	Number of days from today to expiry date
Path (Optional)	String	Access path (see 'A quick cookie primer')
Example: setCookie("UserName", Uname, 365, "/") This creates a cookie called UserName, with a value equal to the variable Uname, an expiry date 365 days from today, and a path of "/" (so any page from the same domain (website) can access it). Note that the function generates the expiry date automatically - you just have to specify a lifespan period in days. To create a cookie with a specific expiry date, use the setDatedCookie() function instead. This takes a date object for its expiry parameter, instead of period of days. Here's an example: tdate = new Date(2004, 10, 5) setDatedCookie("UserName", Uname, tdate, "/") Apart from the expiry date, setDatedCookie() is identical to setCookie(). These functions don't directly support the domain= setting. However you can add one to the path specification, like this: setCookie("UserName", Uname, 365, "/; domain=mydomain.com")

deleteCookie(Name, Path) deletes the specified cookie.
Parameter	Data Type	Meaning
Name	String	Name of cookie to delete
Path (optional)	String	Access path - if you created the cookie using a path of "/", then put "/" as the path for deleteCookie()
Example: deleteCookie("UserName") This deletes the cookie called "UserName" by giving it an expiry date of yesterday. It doesn't matter if the cookie doesn't exist - the browser will simply create and delete it in one action.

getCookie(Name) Retrieves the value of the specified cookie from the page's document.cookie string
Parameter	Data Type	Meaning
Name	String	Name of cookie to retrieve
Example: var Uname = getCookie("UserName") This retrieves the value of the cookie "UserName" from the current page's document.cookie string and places it in the variable "Uname". If no cookie called "UserName" is available, the function returns null (a special JavaScript value which is distinct from "").

The source!
If you're using Internet Explorer, then you can click here to download the library file to your hard disk (choose 'Save this program to disk' from the pop-up dialog).

Alternatively, here's the source of the classic cookie functions (see top of page for details of copying and pasting them into your pages):

/*

DISCLAIMER: THESE JAVASCRIPT FUNCTIONS ARE SUPPLIED 'AS IS', WITH
NO WARRANTY EXPRESSED OR IMPLIED. YOU USE THEM AT YOUR OWN RISK.
NEITHER PAUL STEPHENS NOR PC PLUS MAGAZINE ACCEPTS ANY LIABILITY FOR
ANY LOSS OR DAMAGE RESULTING FROM THEIR USE, HOWEVER CAUSED.

Paul Stephens' NetScape-based cookie-handling library

http://web.ukonline.co.uk/paul.stephens/index.htm

TO USE THIS LIBRARY, INSERT ITS CONTENTS IN A <script></script> BLOCK IN THE
<HEAD> SECTION OF YOUR WEB PAGE SOURCE, BEFORE ANY OTHER JAVASCRIPT ROUTINES.

Feel free to use this code, but please leave this comment block in.

*/

function setCookie (name, value, lifespan, access_path) {
var cookietext = name + "=" + escape(value)
if (lifespan != null) {
var today=new Date()
var expiredate = new Date()
expiredate.setTime(today.getTime() + 1000*60*60*24*lifespan)
cookietext += "; expires=" + expiredate.toGMTString()
}
if (access_path != null) {
cookietext += "; PATH="+access_path
}
document.cookie = cookietext
return null
}

function setDatedCookie(name, value, expire, access_path) {
var cookietext = name + "=" + escape(value)
   + ((expire == null) ? "" : ("; expires=" + expire.toGMTString()))
if (access_path != null) {
cookietext += "; PATH="+access_path
}
document.cookie = cookietext
return null
}

function getCookie(Name) {
var search = Name + "="
var CookieString = document.cookie
var result = null
if (CookieString.length > 0) {
    offset = CookieString.indexOf(search)
    if (offset != -1) {
        offset += search.length
        end = CookieString.indexOf(";", offset)
        if (end == -1) {
           end = CookieString.length }
        result = unescape(CookieString.substring(offset, end))
   }
}
return result
}

function deleteCookie(Name, Path) {
setCookie(Name,"Deleted", -1, Path)
}

/* END OF FUNCTIONS */