Update app.py

app.py

@@ -1,4 +1,9 @@
 import streamlit as st
 
 x = st.slider('Select a value')
-st.write(x, 'squared is', x * x)
+st.write(x, 'squared is', x * x)
+
+if st.button('Say hello'):
+    st.write('Why hello there')
+else:
+    st.write('Goodbye')