help on delete trigger.

I am developing a db application in postgresql and i need to write a delete
trigger on one of the tables.

the environment is

table1

field1 varchar(64)
other fields.

table 2.

field1 varchar(64)
other fields

I need a delete trigger on the table 1, so that if I delete a row from table
1 , the corresponding rows from table 2 should also be deleted.

This is the code I have tried.

DROP FUNCTION ApplicationsDeleteFn();
CREATE FUNCTION ApplicationsDeleteFn()
RETURNS OPAQUE
AS '
BEGIN
delete from ports where appName=OLD.appName;
RETURN OLD;

END;
'
LANGUAGE 'plpgsql';

Please help me with this, as my work is time bound.

Thanks
sundar