import streamlit as st

st.title("Demo app with session vars")
if "messages" not in st.session_state:
    st.session_state.messages= []

message_container = st.empty()

message_input = st.text_input("Enter message")

if message_input:
    st.session_state.messages.append(message_input)
    message_input = ""

for message in st.session_state.messages:
    message_container.write(message)