Update app.py

app.py

@@ -60,6 +60,8 @@ if __name__ == "__main__":
                         # saving the vector store in the streamlit session state (to be persistent between reruns)
                         st.session_state.vs = vector_store
                         st.success('File uploaded, chunked and embedded successfully.')
+                else:
+                    st.error("Please drag and drop your file to the upload area above.....")
             else:
                 st.error("Please provide your OpenAI API key above.....")