First version quick fix

app.py

@@ -248,13 +248,14 @@ with st.sidebar:
     st.subheader("An intelligent sales forecasting system")
     uploaded_file = st.file_uploader("Upload your store data here to proceed (must atleast contain Date and Sales)", type=["csv"])
     if uploaded_file is not None:
-      date_found, sales_found = False
+      date_found = False
+      sales_found = False
       for column in uploaded_file.columns:
         if 'Date' in column:  
           date_found = True
         if 'Sales' in column:
           sales_found = True
-        if(date_found and sales_found):
+        if(date_found == False and sales_found == False):
           st.error('Please upload a csv containing both Date and Sales...')
           st.stop()