Update app.py

app.py

@@ -75,7 +75,7 @@ def edit_message(position):
     if st.session_state.messages[position-1]["role"] == "user":
         if st.button("Save & Retry"):
             st.session_state.messages[position-1]["content"] = returnText
-            del session_state.messages[position-1:]
+            del st.session_state.messages[position-1:]
             st.session_state.instant_request = True
             st.rerun()