Availability Check Issue

Hi Friends,

I have issue related to ATP where in scenario 1 while i am creating sales order with reference to a quotation Availability Check screen is appearing and for the same material in scenario 2 while i am creating sales order with reference to a quotation availability check screen is not appearing.

I want in both the scenarios the availability check screen should not appear.

Can some body throw some light as to where this configuration needs to be changed.

Regards,