Just call SetNoStore on the HttpCachePolicy object exposed 
through the Response object's Cache property, as 
demonstrated here:
 
        <%@ Page Language="C#" %>
                  
            <%
              Response.Cache.SetNoStore ();
              Response.Write (DateTime.Now.ToLongTimeString 
());
            %>
          
  
SetNoStore works by returning a Cache-Control: private, no-
store header in the HTTP response. In this example, it 
prevents caching of a Web page that shows the current time.

Write this code in the Page load event of the code behind :-

Response.Cache.SetCacheability(HttpCacheability.NoCache);