Fix SGML typo in previous patch.

doc/src/sgml/ref/alter_table.sgml

 <!--
-$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.37 2002/02/17 11:50:09 momjian Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/ref/alter_table.sgml,v 1.38 2002/02/17 13:29:00 momjian Exp $
 PostgreSQL documentation
 -->
 
@@ -293,7 +293,6 @@ ALTER TABLE distributors ADD CONSTRAINT distfk FOREIGN KEY (address) REFERENCES
 ALTER TABLE distributors ADD CONSTRAINT dist_id_zipcode_key UNIQUE (dist_id, zipcode);
    </programlisting>
   </para>
- </refsect1>
 
   <para> 
    To add an automatically named primary key constraint to a table, noting