Server.MapPath("~/folder/" + filename)

var certificate = new X509Certificate2(Authentication.KeyFilePath, Authentication.KeyFilePassword,
 X509KeyStorageFlags.Exportable);

var certificate = new X509Certificate2(Authentication.KeyFilePath, Authentication.KeyFilePassword,
   X509KeyStorageFlags.MachineKeySet |
   X509KeyStorageFlags.PersistKeySet | 
   X509KeyStorageFlags.Exportable);

    $(document).ready(function () {
        $("#term").autocomplete(url, {
            // ..... 
            extraParams: { id: 12, xyz: "test" }
        }).result(function (evt, row, formatted) {
            // .....
        });
    });