SQL & PL/SQL

Create or replace procedure year_test(var_year varchar2(20))

v_ym INTERVAL YEAR TO MONTH;

BEGIN v_ym := INTERVAL var_year YEAR TO MONTH;

dbms_output.put_line(ROUND(((( EXTRACT (YEAR FROM v_ym)) *12)   (EXTRACT (MONTH FROM v_ym))) * 30.436) || ' Days');

END;

please help me out..i could't rectify the error