Log Message:-----------Improve example for DO, per Petr Jelinek.
Modified Files:-------------- pgsql/doc/src/sgml/ref: do.sgml (r1.1 -> r1.2) (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/do.sgml?r1=1.1&r2=1.2)