updates for dropdown list

app.py

@@ -142,13 +142,15 @@ with gr.Blocks(theme=myTheme) as demo:
     toolkit_select = gr.Dropdown(["OPUS", "NLLB"], label="Select Translation Model")
     lang_select = gr.Radio(["English", "Chinese"], label="Select Desired Language")
     result = gr.Textbox(label="Translated Result")
-    trans_btn = gr.Button("Translate")
+
     toolkit_select.select(on_select)
-    trans_btn.click(fn=opus_trans, inputs=[article, lang_select], outputs=result)
+    # trans_btn.click(fn=opus_trans, inputs=[article, lang_select], outputs=result)
     if toolkit_select.select(on_select) == "OPUS":
         print(" chosen OPUS")
+        trans_btn = gr.Button("Translate")
         trans_btn.click(fn=opus_trans, inputs=[article, lang_select], outputs=result)
     elif toolkit_select.select(on_select) == "NLLB":
         print(" chosen NLLB")
+        trans_btn = gr.Button("Translate")
         trans_btn.click(fn=nllb_trans, inputs=[article, lang_select], outputs=result)
 demo.launch()