HttpContext context compile error

Hi,

I am migrating to Visual 2012. When I build and run the web application in DEBUG mode, I get some compile error which worked on VS 2003. The Session is null for .NET 4.0 and even 3.5. Any help is appreciated to fix the following code to work under VS 2012.
The code is called from the web.conf file
     <httpModules>       <add name="SyncHttpModule" type="MY.Controller.SyncHttpModule, MyProject.WebUI"/>     </httpModules>
 
 
Thanks

            HttpContext context = ((HttpApplication) source).Context;             string _keyword = FrameworkConst.SYNC_CONTROL_KEYWORD;             string sesToken = (string) context.Session[_ke ...