Price field mandatory while creating PR

Dear All,

i have a requirement to make PR price field mandatory for certain PR document types while creating the PR (ME51N). i have tried to the make the price and price unit field required via Define Screen Layout at Document Level but its not working.

what are the alternatives to implement the solution. do i need to use a BADI to make the price field mandatory in ME51N?

expecting prompt responses,

Best Regards,