Update app.py

app.py

@@ -30,12 +30,16 @@ messages = [
 ]
 
 def handle_query(query: str, mode: str):
+    
+    # Check if query is empty
+    if not query.strip():
+        return "Enter a valid message."
     if mode == "Chat":
         return chat_mode(query)
     elif mode == "Web-Search":
         return web_search(query)
     else:
-        return "Invalid mode selected."
+        return "Select a valid mode."
 
 def chat_mode(query: str):
     global messages