Update app.py

app.py

@@ -32,12 +32,12 @@ def start_bot(userid, password, api_key_input):
 
 
 def answer(message, history):
+    if bot is None:
+        return "❗ Please log in first to use the bot."
+    
     answer_md, tables_display, images_display, retrieved_display = bot.get_answer(message)
     
-    # Combine all parts into a single response string for chat
     combined_response = f"{answer_md}\n\n{tables_display}"
-    
-    # Add images as markdown
     if images_display:
         combined_response += "\n\n" + "\n\n".join(images_display)