Update static/script.js

static/script.js

@@ -318,10 +318,10 @@ document.addEventListener('DOMContentLoaded', () => {
 
             const isIdentityEnabled = identifyCheck && identifyCheck.checked;
             const maxSpk = isIdentityEnabled ? parseInt(maxSpeakersSelect.value) : 1;
-
+            const targetLang = subtitleLangSelect ? subtitleLangSelect.value : 'ja';
             socket.emit('start_stream', {
                 url: url,
-                target_lang: subtitleLangSelect.value,
+                target_lang: targetLang,
                 max_speakers: maxSpk
             });
         });