Introduction to Expires Properties

Expires Property
The Expires property specifies how much time is available to cache the paged memory on the browser. If a user returns to this page before a page expires, the version in the buffer is displayed

Grammar
Response.Expires [= number]

Parameters
Number
How many minutes are left before it expires? Setting this parameter to 0 causes the cached page to expire immediately.

Comments
If this property is set more than once on a page, the shortest time is used.

Apply to Response object

Response.expires=0 also indicates an immediate expiration, but cannot expire immediately if the client and server are not in a time zone or the client's time earlier than the server. So use a negative number or use Response.expiresabsolute=now ()-to indicate an immediate expiration, and Response.expires=1 to expire in 1 minutes.