how can fix this error

[smita mishra]

after executing :

declare
pi constant number(5,4) := 3.141;
area number(14,2);
cursor rad_cursor is select * from Radius_vals;
rad_val rad_cursor%ROWTYPE;
begin
open rad_cursor;
loop
fetch rad_cursor into rad_val;
exit when rad_cursor%NOTFOUND;
area := pi * power(rad_val.radius,2);
case
when rad_val.radius = 3
then insert into areas values(rad_val.radius,area);
when rad_val.radius = 4
then insert into areas values(rad_val.radius,area);
when rad_val.radius = 10
then insert into areas values(0,0);
else raise CASE_NOT_FOUND;
end case;
end loop;
close rad_cursor;
end;

this code I got out put:
declare
*
ERROR at line 1:
ORA-06592: CASE not found while executing CASE statement
ORA-06512: at line 19

how can I fix this error.

[Chris Hendy]

At line 19 you explicitly raise a CASE_NOT_FOUND exception if none of the other CASE expressions evaluates to true. Either the PL/SQL itself or the calling program needs to handle the exception.

In PL/SQL you might have an exceptin handler

DECLARE
.
.
BEGIN
.
.
EXCEPTION
WHEN CASE_NOT_FOUND THEN
-- Your own code to Log it or return a user friendly error message
-- to the calling program.
END;