Unflag the Closed Indicator Purchase Requisition

Dear Experts,

While Creating Production Order Based Purchase Requisition the Closed Indicator as Assigned.

Due to this Process Problem we cant change the Purchase Order .it shows the Error "

Materials of requisition 10021627 item 00010 alr. ordered in full - Message no. 06076 ".

Here i can able to change the same PO via ME22 but unable to change ME22N. I have searched the Related Documents

the founded Reason is the Closed Indicator of Purchase Requisition is flagged.My Requirement is How can i Unflag the Closed indicator.

Here am Raising the Purchase Order Manually via ME21N.

Thanks in Advance..

With Regards,

Thangam.P