If You Want to Control Which Cookies You Accept:
You can order your browser to accept all cookies or to alert you every time a cookie is offered. Then you can decide whether to accept one or not.

If you're using Internet Explorer 4.0:
1. Choose View, then
2. Internet Options.
3. Click the Advanced tab,
4. Scroll down to the yellow exclamation icon under Security and choose one of the three options to regulate your use of cookies.

In Internet Explorer 3.0, you can View, Options, Advanced and click on the button that says Warn Before Accepting "Cookies."

If you're using Netscape Communicator 4.0:
On your Task Bar, click:
1. Edit, then
2. Preferences, then
3. Click on Advanced.
4. Set your options in the box labeled "Cookies".

Why did I get a "No cookie" error?
The "No cookie" error message means one of two things:

• The cookie was never received or accepted by your browser, or
• Your browser failed to return the cookie with your request for a page.

In order for this system to work, the server and browser need to work together. Unfortunately, different browsers handle cookies differently. Some browsers don’t handle them at all. And some browsers that should handle cookies don’t, or they don’t under certain circumstances.

The problems with CompuServe have been corrected with the issuance of CompuServe 3.04, which can be requested free of charge by dialing 1-800-48-UNION. If your airline uses CompuServe for bidding, call 1-800-BID-FAST (1-800-243-3278).

How do cookies work?
Cookies are small data structures delivered by a Web site (ALPA) to a Web client (you). The Web site may deliver one or more cookies to the client. The client stores cookie data in one or more flat files on its local hard drive. In certain cases (determined by the data in the cookie itself), the client returns the cookie to the server that originally delivered it.

Can cookies read information from a user's hard drive?
No. Cookies can only store data that is provided by the server or generated by an explicit user action.

Can cookies be used to gather sensitive information, such as a user's e-mail address?
Cookies can be used to store any information that the user volunteers. They cannot be used to gather sensitive information.

Where are cookies stored?
Cookie data is stored unencrypted on the user's hard drive (although during actual communication it is stored in memory). The file name is different for each platform. For example, on Windows machines, cookie data is stored in a file called COOKIE.TXT.

How long do cookies last?
A Web site may set an expiration date for a cookie it delivers. If no expiration date is specified, the cookie is deleted when the user quits the browser.

Can malicious sites read cookie information used by another site?
Cookies are designed to be read only by the site that provides them, not by other sites.

What products support cookies?
Netscape Navigator has supported cookies since version 1.0. Microsoft Internet Explorer has supported cookies since version 2.0.

Does every browser implement cookies in the same way?
Not necessarily. Because the use of cookies is just becoming an official standard, there may be some subtle differences that do not affect how they work. Some browsers use a single file for all cookies, while others use a folder with a separate file for each cookie.

Why are cookies useful?
Cookies allow Web sites to maintain information on a particular user across HTTP connections. The current HTTP protocol is stateless, meaning that the server does not store any information about a particular HTTP transaction; each connection is "fresh" and has no knowledge of any other HTTP transaction. "State" information is information about a communication between a user and a server, similar in many ways to frequent flyer profiles or option settings in desktop software. (For example, a preference for aisle or window seats is cookie-like information that a frequent flyer program might store about one of its customers.) In some cases it is useful to maintain state information about the user across HTTP transactions.

What kind of client-side information can Web servers store?
User information may be stored in the cookie or in a database on the Web site. This information may be provided by either the user or the Web site provider. Some scenarios include the following:

• Alice is shopping at a particular Web site that uses a shopping cart metaphor. She puts items into a shopping cart by clicking a link or an "Add to Shopping Cart" button. Cookies can be used to store or reference information on the contents of Alice's shopping cart so that she can conveniently purchase a cart full of items rather than one item at a time.
• Bob clicks around a Web site that allows users to view articles for a small charge. Cookies can be used to store or reference information about which articles he has viewed (that is, a list of URLs) so that he can pay for them all at once rather than each time he downloads an article.
• Carl fills out a Web form with his name, address, and other information. Cookies can be used to store or reference this information so that the next time Carl visits the site, the information is automatically uploaded and he doesn't have to provide it again. If the form contains sensitive information such as a credit card number or a mailing address, the cookies can be delivered over a Secure Sockets Layer, which encrypts the information as it travels between the client and server.
• Don logs in to a Web site that requires a user name and password. When Don's user name and password pair is successfully verified, the server passes down a cookie that functions as a "guest pass" allowing him access to certain areas of the Web site. After a set time period, perhaps half an hour or a day, the guest pass expires and Don must log in again.