How to bring workflow to Purchase Order approval in Dynamics AX?

Hi all,

We're implementing Dynamics AX 2009 in our organization. Currently we have a process wherein, all the Purchase Orders are sent to an approval authority for approval after which, the Order is placed on Supplier.

According to our implementation partner, Workflow is not available in Purchase Order.

Can anybody suggest how do we go around this?

Thanks and Regards,

MBrown