compilation errors in triggers for delete

Hi,
can anyone please tell me what is wrong with these triggers....I get a 'Warning: Trigger created with compilation error' when i run my shell script. The other trrigers that I have written for insert work fine.
The triggers are:

create or replace trigger T_USER_ACT_CONFIG_delete
before DELETE on T_SMISNODE
for each row
BEGIN
DELETE from T_USER_ACT_CONFIG where Localid=ld.localid;
END;
/

create or replace trigger T_CON_FAIL_CONFIG_delete
before DELETE on T_SMISNODE
for each row
BEGIN
DELETE from T_CON_FAIL_CONFIG where Localid=ld.localid;
END;
/

create or replace trigger T_CON_FAIL_DETAILS_delete
before DELETE on T_SMISNODE
for each row
BEGIN
DELETE from T_CON_FAIL_DETAILS where Localid=ld.localid;
END;
/

Your triggers look fine and suppose to work, first create any of these trigger directly from SQL prompt just to make sure that there is no problem in your trigger, if it gives you any error, you can see where is the error by using 'show errors' command on sql prompt it gives you line number and some information that cause to generate error, for example

SQL>show errors

I think you probably want to refer to ld.localid rather than id.localid

Also, you could look at ON DELETE CASCADE integrity constraints which would automatically delete entries from the child table when the parent table entry is deleted.