You may want to make sure that a client visiting your site cannot cache a particular Web page. However, setting the Response.Expires=0 does not always prevent a browser from caching a page. You will have to add few more lines to your code to programmatically prevent caching. These meta tags always make sure that you get what you ask for:
' Do not allow caching. Response.AddHeader "cache-control", "private" Response.AddHeader "pragma", "no-cache" Response.ExpiresAbsolute = #January 1, 1980 00:00:00# Response.Expires=0