Unable to validate the text with validate trigger

Question

Hi I am facing one issue
I want to validate the password before going to another field, i put the following code on the when validate trigger,what i want if the password is wrong the cursor should go to the password field and clear the contents of that field only.When i put go_item and clear_item its giving error,pls find the following error and my code
FRM-40737:Illegal restricted procedure Clear_block in when validate Item trigger
declare
l_user                     varchar2(6) := null;
l_pass           varchar2(10);
n_pass varchar2(10);
chkbutton number;
chk number;
Begin
select passwd into l_pass
     from Trx_usr
     where username = :USR.DISUSR;
          if      :global.pass = :TRX.PASSWD then
          message('Login Sucesss');
          else
               chk:=show_alert('ALRLOG');
               if chk = alert_button1 then
               go_item('TRX.PASSWD');
               clear_item;
               end if;
          end if;
     end;
rgds
shrey

Answer 1

I guess go call that code in the WHEN-VALIDATE-ITEM-trigger of the password-field itself? So you don't need any GO_ITEM. And instead of using CLEAR_ITEM you can just assign NULL; like
:TRX.PASSWD:=NULL;