How to save Purchase order

Firstly go to the task bar then select the purchase order as:

Then the following window will appear as:

Give the vendor id which we can make if vendor id is not present. When we click on the vendor id the information of the vendor will appear then give the po no. Then give the quantity which is required and then select the item from the magnifier if item is not given then go to inventory and give the item id and description then save it but now when we fill the requirements the following widow will appear as.

And then save it