Update app.py

app.py

@@ -64,8 +64,10 @@ def ask(question, openai_api_key, gemini_api_key, anthropic_api_key, file_name =
         gr.Warning("Anthropic API Key is required.")
         return "", ""
 
-    if not validate_input(question, openai_api_key, gemini_api_key, anthropic_api_key, file_name):
-        gr.Warning("Invalid input.")
+    is_valid, err_msg = validate_input(question, openai_api_key, gemini_api_key, anthropic_api_key, file_name)
+    
+    if not is_valid:
+        gr.Warning(f"Invalid input: {err_msg}")
         return "", ""
     
     if file_name: