Client Tools :: Usage Of Package In 10g Form

I have made a package and define a variable in it as:

CREATE OR REPLACE package Scott.My_Pac as
CNT_UPD_USR Varchar2(20)
END My_Pac;

When I used the following in Toad it works fine but when I use the same in 10g form it gives the error "Cannot directly access remote package variable or cursor".

Begin
Scott.My_Pac.CNT_UPD_USR := 'Ali';
DBMS_OUTPUT.PUT_LINE(Scott.My_Pac.CNT_UPD_USR);
End;