serial no for partialy confirmed qtys

Hi,

Scenario:

In Make to stock Scenario, while creating production order, I am creating serial numbers.

I have 10 operations in routing and confirming those in co11n.

Problem:

I have created production order for 20 Qtys. While partially confirming third operation in co11n, I have confirmed 10 Qtys.

However, I am not getting option to select serial numbers of 10 Qtys that I want to confirm.

Can anybody please guide me for the solution?

Regards,

Samir