default changes

app.py

@@ -60,6 +60,9 @@ if __name__ == "__main__":
     # Autofill the selected question into the text input
     question = st.text_input("Ask a question about the document:", value=selected_question)
 
+    if "messages" not in st.session_state:
+        st.session_state.messages = []
+        
     # Handle user question and AI response
     if st.button("Ask AI") and question:
         st.session_state.messages.append({"role": "user", "content": question})