PR should not allow to change the PR Qty after PO created

Hi Guys,

I'm having a request to enactment power connected me54n. erstwhile PO created idiosyncratic should not let to alteration the PR qty details connected me54n .

example : accidental I person created the PR with 10 qty and I person done po instauration , present again one went to me54n and unrelease the merchandise strategy past alteration the PR qty from 10 to 15. Now one request a power present , strategy should not let the alteration connected PR erstwhile PO created.

can anyone assistance maine connected this....