Price Change Issue

Hi

Dear Experts i created one material with price control "S" and maintain price in Material Master . After some time I changed price control from S to V .

Issue is that system is displaying both price in material master standard & Moving Price . Because i am using price control "v" So i want to delete standard price from material .

I have tried to change it with statistical price in MR21 but not able to update .Plz suggest

With Regards