Prevent Duplicate Insertion on DB When page refresh - Asp.net -

(asp.net) how prevent duplicate records insertion in database when user refreshs page after post back. know can handle redirecting page. , handle through check if same entry exists inside stored procedure. wont full fill requirement sometime. want know there other practice instead redirecting page. (i know can handle using ajax, not using ajax)

try

if (!ispostback)         {                      }