A cookie is removed from the browser when the expiration date is reached. The life time of a cookie with no expiry attribute is the user's session. Life times are given in seconds; the program computes an expiration date based on the current time and the specified life time. A cookie may be removed by specifying a negative life time or by using the ``Delete Cookie'' form.
A cookie may be specified to be secure, which means that the cookie is transmitted on secure channels only (e.g., HTTPS requests using SSL). A value of "No" means that the cookie is sent in clear text on insecure channels (e.g., HTTP requests).