cassinidev server namespace not found

hi there I am trying to create wrapper class for cassnidev server which is a local.web development server used by the VS itself. I refrenced the dll file CassiniDev-lib.dll. then imprted CassiniDev namespace like using CassiniDev; namespace LocalServer { class MyLocalServer { static CassiniDevServer _server =new CassiniDevServer(); public static void browseWebsite(string path) { _server.StartServer(path,1234,"/","localhost") System.Diagnostics.Process.Start("http://localhost:1234/"); } }} while typong.intellisense shows the CassiniDev namespace and class,butwhen I build it it gives warning: the refrence assembly CassiniDev4-lib could not be resolved, it has dependency on System.Web, Version=4.0.0.0..... which is not in the currently targeted framework...... also it gives error as 1.the namespace or type CassiniDev could.not be found (are you missing a using directive or an assmbly refrence) 2. sAme abov error for CassiniDe ...