Material Availability Reserved Against Sales Order

Dear Gurus,

I have configure the system and mark "availability check" at schedule line, lets say 100MT is in stock, if I create a sales order of 101 MT system bring me towards availability screen, that fine.

but when first time I create the SO lets say like 70 MT with batch number, and save the order, how can i configure the system so that in some report stock reservation is shown against that order, and remaining qutuantiy only shown 30 MT.

Please suggest the steps.

regards,

Imran Khan