Prepayment and Credit hold

Hi All

Consider the following scenario:

A sales order is booked with amount greater than order limit. As a result, it is put on hold. now, a prepayment is made for this sales order with amount enough to bring down the net credit (booked amount - prepayment) below order credit limit. It still remains on hold.

I want to know what setups are required so that order is released from credit hold automatically as soon as its net credit becomes lower than order credit limit.

Regards

Deepak Singal