Email Alerts for Data in QlikView

[Anonymous]

I have a data which has Revenue generated by each user everyday. I want to set up an email alert when the revenue for Today is more than 20% less than yesterday's. I am not sure how to set it up. I was trying to use this formula. Sum({<Order_Charged_Date={"$(=Date((Max(C), -1)))"}>}Price_in_USD) for yesterday's revenue but not sure how to compare it with Today's revenue and send an alert.

Any help will be appreciated.

Thanks.

[Gysbert_Wassenaar]

Try this condition:

1 - Sum({<Order_Charged_Date={"$(=Date((Max(C))))"}>}Price_in_USD) 
/ Sum({<Order_Charged_Date={"$(=Date((Max(C), -1)))"}>}Price_in_USD) > 0.2