--- fenglin/bbs/user_service_reg.php	2025/04/27 04:32:05	1.3
+++ fenglin/bbs/user_service_reg.php	2025/11/03 06:19:31	1.5
@@ -34,7 +34,7 @@
 	header("Content-Type:application/json; charset=utf-8");
 
 	// Validate input data
-	if (!preg_match("/^[A-Za-z][A-Za-z0-9]{4,11}$/", $username))
+	if (!preg_match("/^[A-Za-z][A-Za-z0-9_]{4,11}$/", $username))
 	{
 		$result_set["return"]["code"] = -1;
 		array_push($result_set["return"]["errorFields"], array(
@@ -338,4 +338,3 @@
 
 	mysqli_close($db_conn);
 	exit(json_encode($result_set));
-?>