The correct method of deleting a cookie is to set its "expires" timestamp to some time in the past (e.g. expires=Wednesday, 31-Dec-1990 00:00:00 GMT). You will need to make sure that all other clauses in the cookie header, INCLUDING the "path", are identical to what they were when the cookie was originally sent.
If you are seeing inconsistent behavior between browsers and/or operating systems, then my guess is that your cookie headers are incorrect and that some browsers are more forgiving than others.
The FoxWeb 2.X documentation contains information on some of the things to watch when setting cookies from your scripts. Some of the information is specific to FoxWeb 2.X, but the general cookie concepts are the same. Look for the Disappearing session variables and cookies section in http://www.foxweb.com/document/trouble.htm.
Sent by Gary Farrell on 08/18/2004 09:26:21 AM:
We are running an application using Foxweb 1.29. During the course of the application we ar setting and reading cookies. After an order has been placed we clear certain cookies (by setting their values to blank) and send the user back to the main product page.
This works for the vast majority of users, but on certain machines running IE 6.0 with XP Pro the cookies remain set. Other users who use IE 6.0 with XP Pro do not have the problem.
Should I use some other method to clear the cookies, or is it something in the security settings?