HttpResponse::Expires Property
Gets or sets the number of minutes before a page cached on a browser expires. If the user returns to the same page before it expires, the cached version is displayed. Expires is provided for compatibility with earlier versions of ASP.
Assembly: System.Web (in System.Web.dll)
The Expires, ExpiresAbsolute and CacheControl properties have been deprecated in favor of the methods of the HttpCachePolicy class available through the Cache intrinsic object to control the Internet Information Services (IIS) output cache and client caches.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.