See the codex. The first parameter is format, the second is link text.
<?php previous_post_link('<strong>%link</strong>', '«'); ?>
<?php next_post_link('<strong>%link</strong>', '»'); ?>
See the codex. The first parameter is format, the second is link text.
<?php previous_post_link('<strong>%link</strong>', '«'); ?>
<?php next_post_link('<strong>%link</strong>', '»'); ?>