Paul:

It may be just me, but I believe that the "include_once" statements
below should be "require_once", actually. Eh?

src/addrbook_search_html.php

@@ -23,7 +23,7 @@ require_once('../functions/smtp.php');
 require_once('../functions/display_messages.php');
 require_once('../functions/addressbook.php');
 require_once('../functions/plugin.php');
-include_once('../functions/strings.php');
+require_once('../functions/strings.php');
 
 /* Insert hidden data */
 function addr_insert_hidden() {

src/addressbook.php

@@ -15,7 +15,7 @@ require_once('../src/validate.php');
 require_once('../functions/array.php');
 require_once('../functions/display_messages.php');
 require_once('../functions/addressbook.php');
-include_once('../functions/strings.php');
+require_once('../functions/strings.php');
 
 /* Make an input field */
 function adressbook_inp_field($label, $field, $name, $size, $values, $add) {