Not performing availability check..............?

Hi,

While i am creating sales order system is performing availability check.....

below configuration i have done ....

1. i maintained availability check in material master

2. in sales document system determines schedule line category as CP, so i checked Availability field and requirement field in VOV6.

3. i maintained availability field check and requirement field check in requirement class.

4. and also requirement type determined into sales document Procurement tab.