diff --git a/booking.regn_form.inc b/booking.regn_form.inc
index 4955983..c22b121 100644
--- a/booking.regn_form.inc
+++ b/booking.regn_form.inc
@@ -71,7 +71,7 @@ function booking_register_page()
 function _booking_ecclesia_name_autocomplete($string) {
   $matches = array();
   $sanitised_string = preg_replace("/[^a-zA-Z0-9\s\.']/", '', $string);
-  $sanitised_string += "%";
+  $sanitised_string .= "%";
   watchdog('booking_debug', "<pre>Autocomplete checking for ecclesia matching:\n@info</pre>", array('@info' => print_r($sanitised_string, true)));
 
 	$query = db_select('booking_person', 'p')