Logic help /


I dont have very much experience in navision and i need your help now.

I need for the Notificaitons on navision.

How can i compare the Items inventory with safety stock quantity.
I mean in all sales or something the number of inventory is going less. How can i compare it with the safety stock quantity every time where any sale of inventory is done, ore if number of inventories is less then safety stock quantity.

is it any trigger or something where can i compare it.