Variables are created when they are referenced, and until set they
have the value empty string (just like the shell). Across file
-reloads, the previous values of variables is preserved.
+reloads, the previous values of variables are preserved.
To initialize a variable to a known value when the jobs file is
loaded, call one of the C<Whentools.set_variable*> functions as in
=item B<Whentools.mailto> [I<~only_on_failure:true>]
[I<~from:from_address>] I<email_address> I<result>
-Send the result of the script by email to the given email address.
+This built-in post function sends the result of the script by email to
+the given email address.
If the optional C<~only_on_failure:true> flag is set, then it is only
sent out if the script failed.