Inactivating a Quote

 Hi Team,

Currently on Quote/Sales Order Header we have a Active check box, which when Unchecked makes the record Read Only. Once we check this Active Check box the Record Becomes editable again. This Activating and In activating the Quote Record is done manually as per vanilla process.

But i have a requirement where if my quote due date is equal to System date, automatically the Active check box should be unchecked. this should happen even if we are not accessing the record or even though if we are not logged on to siebel application. when ever my quote due date and my system date is equal, the Active check box should be unchecked.