Update app.

app.py

@@ -360,8 +360,8 @@ def main():
 
 
     if submit:
-        if ex_s != '...': 
-          st.warning('Please choose an example.')
+        if all(len(v)==0 for v in user_input.values()): 
+          st.warning('Please choose an example, or provide input.')
         else:
             with st.spinner("Processing (may take a couple of minutes) ..."):
                 output = run_model(modes_s,user_input)