diff --git a/www/main.js b/www/main.js
index f763ee0..d15ae4a 100644
--- a/www/main.js
+++ b/www/main.js
@@ -10,6 +10,7 @@ let bluetooth_mac_input = document.getElementById('bt_mac');
 function switchDevice() {
     bluetooth_mac_input.value = device_selection.selectedOptions[0].value;
 }
+device_selection.addEventListener('input', switchDevice);
 if (device_selection != null && refresh_device_button != null && bluetooth_mac_input != null) {
     refresh_device_button.addEventListener('click', event => {
         notice(i18N.get('Searching devices. Please wait for 5 seconds.'));
diff --git a/www/print-image.html b/www/print-image.html
index 1c8f1a0..e4fb44d 100644
--- a/www/print-image.html
+++ b/www/print-image.html
@@ -36,6 +36,7 @@ Threshold:=阈值：
 Please preview image first=请先预览图像
 Searching devices. Please wait for 5 seconds.=正在查找设备。请等候 5 秒。
 OK=完成
+Printing, please wait.=打印中，请稍候。
     </textarea>
     <script src="i18n.js"></script>
     <script src="main.js"></script>