fixed documentation to reference set_rules() vs set_rule()
diff --git a/user_guide/libraries/form_validation.html b/user_guide/libraries/form_validation.html
index b49117e..31fd6e9 100644
--- a/user_guide/libraries/form_validation.html
+++ b/user_guide/libraries/form_validation.html
@@ -1110,7 +1110,7 @@
<p>The following functions are intended for use in your controller functions.</p>
-<h2>$this->form_validation->set_rule();</h2>
+<h2>$this->form_validation->set_rules();</h2>
<p>Permits you to set validation rules, as described in the tutorial sections above:</p>