> Another question: suspend after exception is not necessary?

After you call exception, no other code is executed (unless you have a
when ... do block which handles the exception), so in your procedure
it will do absolutely nothing and is not required.

An explanation to your other problem is that

select blah
from table
into :blah

will not affect the contents of the variable blah if no result is
returned by the select. This can be a 'gotcha' as some people expect
it to be null, but in truth it will be whatever it was before the
select was run.

Adam