Forum Post: Can a PO req be re-approved if the amount i changed to a higher amount

I have a request to setup a workflow where an approved PO Req amount has increased. I can see where i can set a parameter to compare the line extended cost to the Originating line extended cost. but if the PO is already approved will this trigger a new approval needed? Also how can i get a dollar amount threshold. example: if the difference is greater than $100.00