hi kalik,
            After a long pause, I've successfully done my authorization of my radius server by using digest and perl authentication in mixed mode, as per your advice I put the digest entry first before the perl authentication in the default file, and after that I've put a line of perl code RAD_CHECK{'Cleartext-Password'} = $mypassword, where the password is fetch from the database.  And finally the server starts reading  the cleartext password and starts calculating the md5 encryption and sucessfully  authorized a user.

Lastly, I thank to all the members  of this forum who are dedicated  here to help solving the complex problem in a complicated environment, especially Evan Kalik who is much envolved, regarding my problems of not getting my digest attributes.

Thanking you for your valuable time and consideration.

With Regards,
Johnson Elangbam