Purchase Order Vs Purchase Invoice

I would like to link with the purchase order to purchase invoice via P.O No. Is it possible in Manager? I also would like to track those purchase orders which turns into purchase invoice. How I can do it?

use the Copy To function.
read the guides about it.

I have used that copy function. However, the tally between the purchase order and purchase invoice is required. How can I do that?

you need to provide more details. what should tally? provide some screenshots.