change in to in_list
diff --git a/system/language/english/form_validation_lang.php b/system/language/english/form_validation_lang.php
index a66e192..75d6e4b 100644
--- a/system/language/english/form_validation_lang.php
+++ b/system/language/english/form_validation_lang.php
@@ -65,4 +65,4 @@
$lang['form_validation_greater_than'] = 'The {field} field must contain a number greater than {param}.';
$lang['form_validation_greater_than_equal_to'] = 'The {field} field must contain a number greater than or equal to {param}.';
$lang['form_validation_error_message_not_set'] = 'Unable to access an error message corresponding to your field name {field}.';
-$lang['form_validation_in'] = 'The {field} field must be one of: {param}.';
+$lang['form_validation_in_list'] = 'The {field} field must be one of: {param}.';