bug fix

app.py

@@ -89,17 +89,17 @@ def main():
     user_question = st.text_input('Enter your message here:')
     pdf_file = st.file_uploader("Upload PDF", type=['pdf'])
     if st.button('Start Chain'):
-        with st.spinner('Working in progress ...'):
-            if pdf_file is not None:
+        if pdf_file is not None:
+            with st.spinner('Working in progress ...'):
                 pdf_text = get_pdf_text(pdf_file)
                 pdf_text_chunks = get_pdf_text_chunks(pdf_text)
                 st.session_state.vector_store = create_vector_store(pdf_text_chunks)
                 st.session_state.conversation = get_conversation_chain(
-                    retriever=st.session_state.vector_store,
+                retriever=st.session_state.vector_store,
                 )
-                st.success('Vectorstore created successfully! You can start chatting now!')
-            else:
-                st.warning('Please upload a PDF file first!')
+        st.success('Vectorstore created successfully! You can start chatting now!')
+    else:
+        st.warning('Please upload a PDF file first!')
 
 
     if user_question: