PO Approval

Hi,

Can anybody help me with the following scenario.

I am trying to configuring the PO approval process(3 approver in route code) with below scenario.

1. After generating the purchase order mail should go to first approver(from originator's id) for approval of order.

2. As soon as first approver approves the order then system should send two mail, one is to originator and another one is to second approver.

3. As soon as second approver approves the order then system again send two mail, one is to originator and another one is to third approver.

4. As soon as third approver approves the order then system send mail to originator.